Take it to a gunsmith
Best bet is to find a gunsmith
how do i breakdown and my gun bryco arms 32 cal
Try e-gunparts.com, gun shops, gun shows, want ads.
What Model 51 pistol or a rifle and what model?
Best to ask a gunsmith for help
Best left to a gunsmith
The Western Auto model 117 was made by Mossberg which marketed the gun as the model 402. The 402 was produced from 1961 to 1969. The 402 is a carbine (shorter) version of the Mossberg 400 model. It is a lever action .22 cal rifle. The Mossberg manual may be easier to find than the Western Auto. You can find a schematic drawing and parts break down in "The Gun Parts Corp" catalog. See the link.
You need a gunsmith
Ask a gunsmith for assistance.
Ask for help at a gunshop
Best to get help from a qualified gunsmith.
IIRC, you can request a manual from Browning at Browning.com