steve004 said
.351 SL brass presents a challenge.  Mainly because the big ammunition manufacturers haven't made it for many years.  Handloaders have used a variety of methods to make their own.  In more recent times, the .357 Maximum and .360 Dan Wesson seem to be the most workable candidates for a parent case for alteration.  For those on a budget, .223 cases have been made to work.
I have fired .351's (and .32 SL's and .35 SL's) while standing in grass.  Wow - these cases have a knack for disappearing quick!  Here's a tip:  go back at night with a flashlight and you can find the ones you missed.
  

I’m planning to take my $40 metal detector with me.  It’s not the best, but it works. The kids play with it and for things like this, it will save you a lot of time.  

I have fired .351's (and .32 SL's and .35 SL's) while standing in grass.  Wow - these cases have a knack for disappearing quick!  Here's a tip:  go back at night with a flashlight and you can find the ones you missed.

Bert

Jeremy P said
What ammo were you using? A friend is trying to get his to function and we think it's ammo. Do you have a set of calipers by chance? Would like know overall length of the cartridge 
  

https://winchestercollector.org/forum/winchester-rifles/the-power-of-the-351-sl/

https://www.buffaloarms.com/winchester-highly-finished-arm-bokwhfac.html

Michael - that would be very cool if the serial numbers were included in the descriptions but alas they were not.

There were over 50 Model 1892's, the majority of them quite special.  There was a musket, a cutaway carbine, a cutaway rifle, a whole lot of Trapper carbines, in all chamberings, and quite the variety of barrel lengths - starting at 12 inches - and including 17 inch.  Also an engraved Trapper, a "MGM Movie gun", a smooth bore short rifle, a 14-inch octagon barrel short rifle and then one of my favorites, a 15 inch round barrel short rifle with full magazine, pistol grip and shotgun butt (pictured in the Winchester Handbook by Madis). 

It would be helpful for me to have your attitude about Trapper carbines.  That would have spared me much envy-induced agony. 

steve004 said

Here is another example of crazy supposed values of a rifle.  I have now seen this rifle for sale four individual times in 8 years.  It was first sold at Julia's in March of 2018 for $9200.  It was subsequently listed at Merz for $15,000.  Then, in October of 2025 it was "sold at RIA" for $5875!!!  THEN.. agian it was listed at Merz in March of 2026 for $27,500 where it still sits.  https://www.merzantiques.com/product/w4463-special-order-winchester-1892-pistol-grip-checkered-rifle-in-caliber-25-20-m/
Back to your original question.  The OP's trapper is probably worth someplace between $6000 and $20,000.  Or much higher if the Poulin buyer, and his competition are still in the game.  Or maybe not.
Michael
  

Michael - 
Not to make this a competition but I've seen it for sale more times than four.  And Merz has had it up for offer at least three times - spanning 37 years. Here it is in his 1990 catalog.  A large part of his catalog #67 featured the James Huntley Model 1892 short rifle and trapper carbine collection.  This rifle was mixed in with it so I wonder if Jim hadn't owned it?
I sure wouldn't have minded buying it for $5875!  I wouldn't even mind paying the juice on that amount.
  

WOW!!  That is amazing to have and resold that rifle so many times.  Any chance that the catalog has more 1892 rifles with the serial numbers listed?

Michael