When they arrived, also on JOC'S advice Barrett had his gunsmith install a Griffin & Howe detachable side mount and fit scopes. Expensive, large, bulletproof and ugly, these were said to be reliable and would return a scope to its original zero. 

My point is that, at the time of writing, the two rifles had been twice refinished because of Barrett's extensive use and he had by then replaced the G&H mounts with the Echo mount. He wrote the latter was less inclined to hang up in brush and inadvertently open or loosen the scope's secure attachment. 

The G & H mount does have two tall and prominent on/off levers. Its not-tiny base is attached to the receiver sidewall permanently with several screws but also with large diameter steel pins to assist in resisting recoil-induced movement. The amount of wood removed from the stock and the size and number of holes in the receiver wall are hard to ignore if the base should be removed. 

Barrett was primarily a fisherman who also enjoyed bird hunting and fine shotguns. He was not a collector of pristine firearms. 

Louis Luttrell said
Pictures below from Kevin.  Does anyone recognize the pattern of holes?  It certainly isn't G&H...  

Based on a rough estimate of the hole spacing it looks like it could have been an E. C. Herkner "Echo" Mount.  The Echo mount had a plate that was screwed to the left side of the receiver (requiring a little relief of the stock) and had a removable base and rings that attached to it.  It came with 3 mounting holes for the Model 70 but due to the receiver surface hardness MANY people gave up on the third (middle) hole.  

Here is a link to one on eBay so you can see the complete set-up.  It was one of the better (reasonably priced) removable mounts at the time.

https://www.ebay.com/itm/820098923734

If you can give us the exact CtC hole spacing that will help narrow it down also.

Another option is that Echo made a "blank" base mount (no holes) so you can drill the base to match your existing holes.  They are usually hard to find new/undrilled but there happens to be one on eBay right now - https://www.ebay.com/itm/168698182259   It is for a flat side receiver and is the later aluminum (Colorado address) base instead of the earlier steel (Idaho address) base and won't work for your rifle but you get the idea.

Best Regards,

I was able to score a pretty good deal on a 1951-era, M70 in 30/06, because someone had done the very same to this otherwise very nice rifle.

This rifle came to me WITH the “ugly” Pachmeyr mount installed!

I took it home for only $400 OTD!

When home, I removed the mount and installed some screws in the extra holes to “dissuade” my critical eyes from them.
It did help!

I figure when it comes time to sell this rifle, the mount will be included!

There was a time, back here in western Connecticut, that the late Harry Haight, gunsmith extraordinaire, must have had an “in” with Pachmeyr ‘cause his handiwork was very prevalent around these parts!

Can you send photos of the left side of the receiver and stock to me at luttrell@musc.edu?  I will post them for you.  Alternativelly you'll need to post them on a third party site and post the link here.

With pics, we may be able to determine what brand side mount was originally installed.  There are about a hlaf dozen possibilities...

Lou

Bert

I was recently given a pre-64 model 70 by a family member who is an avid collector. I believe it's a 'pre-war' or close to it (serial number 59,XXX) and has been kept in relatively good condition, except that early on the first owner installed a scope side mount that required a cut into the stock and some drilling. This isn't the cutout for a Lyman peep sight; it's a narrow groove that as best I can tell is for something like the Pachmayr Lo-Swing or Griffin and Howe.

Of course it is usable in its current condition (it's currently set up with a Lyman 48WJS) but I am interested to know more about my options and thought this forum might have some opinions. I think the easiest solution would be to find a smith who can simply fix the stock, but given that the cutout and drilling already exists, is it possible and/or advisable to find and install the appropriate side mount that was originally installed? If so, how do I determine which side mount was used, and how do I understand my options for what kind of scope could be mounted? Though I don't care too much about the sale value (I don't intend to ever sell it), I also don't want to do anything to cause further damage, like further drilling. My goal is to end up with a high-quality shooting/hunting rifle that respects and honors the family heritage of the gun and of the people who used it before me. 

Edit:

Maybe, just maybe, did it say, "bolt turn down like Mouser"?

I like the turned down bolt:

https://bid.lsbauctions.com/online-auctions/lock-stock-and-barrel/winchester-3rd-model-1883-hotchkiss-musket-45-70-govt-bolt-action-rifle-1895-antique-9906806

Bill Jokela said
twobit
I have one model 61 with an X suffix. It is serial number 201072X. I sent this number to you 5 or 6 years ago along with others. It is the only 61 with an X suffix that I have ever seen.
Regards Bill Jokela
  

Hello Bill,

Thanks so much.  I did not have it in my data!  Can't tell you why.  Now it's the only one that I have seen.

Michael

I have one model 61 with an X suffix. It is serial number 201072X. I sent this number to you 5 or 6 years ago along with others. It is the only 61 with an X suffix that I have ever seen.

Regards Bill Jokela

Michael

This is from an older (January 2025) version of the M70 survey, but I think it shows that duplicates were more common at some times than others.  Also shown are the three "D" serial numbers I had at the time and the "G" prefix serial numbers.  The latter represent pre-64 M70 receivers that were replaced after 1968, by which time Winchester was required to add a hand stamped "G" prefix.

Tedk said
Very informative thread…
  

That's for sure!