You have a 1965 Winchester RIOT Gun whose serial number was stamped on December 04 1964, and it has the 1964-65 Checkering.

There is an abbreviated excerpt from my Model 1200 Data Base showing the date I acquired the data and the # Stamping date.  I still have a few slots to fill, but there were a lot of "RIOT" and "Trench Guns" made in that period. Some I have identified as "Prototypes" for the Vietnam Trench Guns.  I ma sure that in the 1965-1967 period made RIOT guns with checkered stocks and Jewelled bolts at the customer's request, and your gun fits well with BigGuy72's guns
I prefer to look at photos when commenting on a gun so will say no more now.  I have written to three NHPD police jusisdictions but no answer yet;

# 169000

# 169319 Winchester Model 1200 12 Ga 30in plain Barrel, Full Choke  - Stamped Dec-01,1964

# 169707 Model 1200 (RIOT) TRENCH 12ga 20” mocked Vietnam style Trench gun Pl Lifter  Pl Stk Blk Butt Pl Pl Farm Jew Bolt Replica   10/29/2012 Stamped Dec-01, 1964 

# 170000+

# 17XXXX Model 1200 -12Ga VR FULL Bl Fluted 3 Dia Chk Stk with Sm Wing & >==== < Farm

# 170194 Riot Gun U.S. Navy endurance test 1964 18" bl, Jeff Moeller. Stamped Dec-03, 1964 06-2026

# 170393 Winchester Model 1200 in 12 ga 30in Pl FULL Bl Stamped Dec-03 1964

# 170447 Model 1200 12 Ga 20in “TRENCH” Bl Barrel heat shield & late style perforated handguard with M5 Bayonet Lug and sling swivel   The checkering is attractive and sharp. Winchester vented rubber buttpad, & press-checkered pump-grip. NOT A TRUE Trench gun 2-2025  Stamped Dec-03 1964

# 171000

# 171294 Model 1200 Riot Gun 12 Ga stamped “NHPD 36″ -2 and 3/4” ch &“jewelled bolt”. 18″ barrel marked “RIOT” Stamped Dec-04, 1964 09-2026

# 172000

# 172XXX Model 1200 12 Ga 28“Pl Bl Jew Bolt 2/12/2014   

# 172236 Model 1200 12 Ga 21in Bl Trench Gun Prototype – S.Landman 06-2026 Stamped Dec-09, 1964

# 173000

# 174000

# 175000

# 176000

# 176779 Model 1200 12ga w/ 4 Bl set including, ONE 30" with fixed Full choke, ONE 28" with fixed Mod choke, One 26" with fixed Imp Cyl choke, ONE 22" sm0oth bore DEER SLUG barrel with rifle sights, ALL 2-3/4" chamber, Red W PG Cap GB 246064235 DIAMOND SILT, CO 81652-9587 No Barrel Address  6 Photos Warranty + Red Box 1966  Woodwork   8/9/2011   Stamped Dec-22 1964

# 177000

Corey Freeman said
That's interesting about the handle.
I was not aware that there was a different length for the early 1897s. Can you tell me what I should be looking for to make it at least look period correct?
  

Corey,

There is no length difference in the early Model 1897 slide handle stocks.  The first difference is the transition from the 3-screw style (Pre-C and C-series) to the D-series slide handles (with no screws), but the length stated the same.  In total, just three variations of slide handle stocks were used for the Model 1897 (97).  Refer to my recent article in the Spring 2026 Collector magazine - 2026 Spring (winchestercollector.org)

Bert

Special ordered 2.5" shells for it.

It worked great.

I do have a "Normal Operation" question. When the shells are loaded, are they supposed to be held in by the lip under the bolt or just by the loading gate?

This gun only retains them by the loading gate. 

I was not aware that there was a different length for the early 1897s. Can you tell me what I should be looking for to make it at least look period correct?

I do not know if a corncob style reproduction is available, I am thinking no. 

I've been well pleased with Mike's work and his turnaround is fast. I think he had my old 31 barrel for a day, no more than 2. Mike cut it back to 27" reset the bead, and supplied 3 chokes for the newly machined barrel. A touch over 200 bucks a few years ago.

Bert

Bert

That is all I have found so far. Don