Photo is too small to tell much. Is there an ID tag on it anyplace?
I don't know much about 2-way radios but I'm over 50 and can't remember not having one around. Everything from Buddy and Citi-fone to Icom and Kenwood.
The radio you have is a Yaesu (Vertex) FTL-2011, 99 channel, 40 watt 134-174 mhz coverage. Great radio, has a alpha-numeric display and multiple format tone encoder / decoder
I've just bought the 2014 (the 4-channel version) and I posted a link for the schematic. RadioArena have the cables at £14 or so (but be sure to buy the right one for your rig) and you'll probably have to find an old computer that can run DOS (from boot-up, not in a "DOS window") for the programming.
If you don't already have it, message me with your email address and I can send you the User Manual.