Your best bet is to go online and do a search for "Airgun Repair" and locate a shop near you that repairs older airguns. there are several that do this type of work as a living.
Walther
I went to www.Carl-walther.de and found this in the Download section. I searched for LG55 http://www.carl-walther.info/dev2/files/pdf/LG55%202223091.pdf
THIS IS A CROSMAN. It is a Crosman model 140 or 1400
I suggest that you go to the Crosman homepage ( they own Benjamin) and click on "Download a manual" there you will find the owners manual and parts diagram for your rifle. See related link.
website for gunpartscorp, letter S, Savage, Model 73, and there is a parts diagram.
See the link below for the parts diagram.
22 Long Rifle
try egunparts
I would contact Walther directly and ask for a parts drawing. See the link below
See related links I put a pointer to e-gunparts.com for the model 16, the have many schematics there as well as the parts page online.
Your best bet is to contact Daisy directly and request a parts diagram if they have one.
I would contact Daisy directly at the link below and ask them.