Need help identifying old 3 handle shower

No idea what brand this is please help!!!!

What I do know is that house was built in 1978 the fixture is original.

Also I have no idea if the remaining handle is original hardware, my dad who originally bought house was the umm how can I say this correctly, lol a shadetree rigging plumber. I do know he had worked on valves in the past and he is known for finding whatever he can that somewhat fits... so as stated earlier handle may not be correct lol

anyway here are some pics

Remove the diverter stem and post a couple of pics of it. You can remove the diverter stem with out turning off the water.

Looks like Sayco to me.
http://www.faucetpartsplus.com/product_p/405453.htm

ok i got the diverter out dont see anykind of identifying marks here are pics.

it measures right at 4 3/4" in legth

You sir are correct after extensive online comparison to sayco stems I was able to properly identify. Only problem is nobody locally where I live carries the replacement kits I have to purchase all items separately which has become expensive. 8 do however thank you for your help.