Go to
http://www.powersportspro.com and sign up for the OEM Parts Fish area. Locate the Honda CR125M 1976 model and add it to your garage. Then browse the on-line fiche at your leisure. You'll notice you can't see the Honda part # in the parts listing under the diagram. However, if you select the part(s) as if you are going to buy them, the Honda part # shows up against each item in your shopping cart. Note down the numbers and then delete the item from your cart if you don't want it. I found that these folks are OK for some parts for the 1979 CR250R and 1983 CR480R but a lot of stuff is discontinued which they inform you later by email. Honda part # in hand I head on over to either
http://www.westernhillshonda.com or
http://www.cmsnl.com who buy up NOS old stock. They do not have on-line fiche, but you can search their inventories by model code or part #.