Most came with a tooth ramped iron sight.But there could be different styles depending on the age of your Winchester model 1894 rifle,such as a peep sight,a full buckhorn sight,etc.
Requires professional appraisal.
Start with gunpartscorp.com then eBay and auctionarms.com
The standard mod 70 had a Winchester bead front sight on a ramp base with a sight cover. The standard rear sight was a Winchester 22G open sight. The rifles chambered for .375 H&H Mag had the Lyman 6W folding rear sight. Model 70 National Match (chambered for .30-06 only) had a Lyman No. 77 front sight on a forged ramp sight base and a Lyman No. 48WH rear sight. All receivers were tapped and drilled for popular scope and iron sights. The Model 70 Super Grade had a Redfield full gold bead front sight on a ramp with sight cover and a Winchester 22G open rear sight. (with acknowledgement to The Gun Digest, seventh edition, 1953)
drift out with punch from left to right, muzzle pointed away from you.
adjust rear sight up for distance
Unless a different sight was special-ordered, it would have come with the Series 26 rear sight, which was made in-house by Winchester. firstname.lastname@example.org
the Winchester 1890 is a fine 22 cal plinker. check with 'Gunbrokers.com' and look under winchester 1890 model for sale price
I would start my search at numrich gun parts corp.They can be found on the web.
You will need the help of a gunsmith.
Use Google and search for '1917 Enfield rear sight'. There are a number of websites that can help you with disassembly, etc. Start with www.cruffler.com
The Winchester Model 68 bolt action single shot .22 was made from 1934-46. It did not have a rear sight mounted on the barrel, but had a receiver mounted Winchester No. 96A peep sight (books at $20-40). As options, Winchester offered the Lyman No. 55W or 57ES Receiver Sights ($25-75). The hunt for old gunsights can pretty interesting. Lyman is still in business, and may be of some help. Good luck. By the way, the rifle (with sights) books from $275 at 100% to $50 at 60% condition.
Use a punch and tap it across the barrel. Its a dove tail joint.