For Beef and a Weck, Schwabl's is hard to beat. I've been enjoying it for 25 years on visits and I guess they've been at it for about 200 years before I got there. Never paid close attention, but I seem to recall Center and Union as a location.
Seconding the recommendation for the Anchor's wings. Might as well visit the place where it all started. (There was rumor a few years ago that Anchor was going to move up the road toward Williamsville. Unknown as to fact.)
Also check out Hoak's near Hamburg and Bay View (just south of Bflo) hard by the lakeshore. Ten years since I was there, but it was great.
Steve's Pig and Ox Roast on Ridge Rd in Lackawanna was also a very good lunch spot. (Same time span.)