It depends on the model rifle--there are three different variants of the Lyman, one for the early round-style bolt releases (1900-1910 models, plus other early Mannlicher designs), one for the 1924-1950 models, and a final version for subsequent models. The first version came with a complete replacement bolt release, while the two later versions mounted to the existing factory release. Hope this helps!
Check the bolt release hinge point on your rifle also.
Different models have either two lugs on the rifle, and one on the sight; or the other way around. I'm not sure of Lyman's numbers, they are usually written by hand on the end of the box.