I can't quite make out all the markings from your picture.
Oneida Victor are still in business in Cleveland, and make still make the No. 5 at 450.00 plus shipping.
The pan will say Cleveland on it, and I would guess yours is older, pre-1976.
There are books on these old traps, however, for a quick look Fur-Fish-Game has a recurring series on old traps and they are on-line.
Search furfishgame Newhouse bear traps and furfishgame beware of fakes.
I can't seem to copy the links, but a quote is pasted below.
From around 1895 to 1911, Newhouse bear traps had S. Newhouse Oneida Community N.Y in raised letters on the pan; they were built in sizes No. 6, No. 5, No. 15, No. 50 and No. 150. From 1911 through 1925, S. Newhouse Oneida Community N.Y PAT. Sept 26-1911 appeared in raised letters on the pans, and collectors refer to these as the patent date model; they were made in all of the same sizes.
In 1925, Oneida sold the trap-making division to Animal Trap Company of America, Lititz, PA, where the Newhouse bear traps were continued in limited production through 1976. The raised letter pan now read Oneida Newhouse Reg.U.S. Pat. Off. Made in U.S.A., Animal Trap Co. Lititz, PA; they were made in sizes No. 6, No. 5, No.15, No. 50 and No. 150.
The value of Newhouse bear traps varies greatly, but all are collectible. Condition and knowing that the parts are original is of most importance when buying these traps. A good No. 6 Slick Pan could bring $8,000 while a No. 5 or No. 15 might fetch up to $800.
Hope this helps.