Use the search button at the top of the page and search '631 non Ladysmith' and you'll pull several previous threads on the issue. Here's one:
Model 631
Supposedly some 5500 of these were made with only 190 being the two inch non LS putting a hefty rarity factor on them. However, I've seen quite a few for sale on GB and elsewhere and believe the number produced to be considerably higher than 190; just my opinion though. I would not be willing to pay double (or more) the price of a LS marked gun. I do like the little 32 631s though and have a four inch and one of the two inch LSs. Good luck.
Jeff
SWCA #1457