Gun shop, pawn shop, gun show, want ad
If you don't have a manual, find a good gunsmith.
You can find them new online for around $150, although the Hi-Point website list the msrp as $186.00 bull i got one on sale $300.00
1946
Smith and Wesson
50-125 or so
You can find out at Proofhouse.com
try the gunpartscorp.com
Find a gunshop and ask for help
Pre 1950
No published sn data
I could not find any 380 cal. pistol going back to 1887 ??? are you sure it's not a 38 cal. revolver ???? check writting on top of barrel ......................
Follow instructions in owner's manual. If you don't have one, find a gunsmith.