You can get some information on the engine if you follow the leads from this page:
http://www.stationary-engine.net/forum/showthread.php?t=3261

You may need to join the forum (it's free) to read the posts - I don't know, I'm a member so I'm automatically logged in. Incidentally it seems the Suffolk 75G14 was marketed as the Suffolk Punch or Super Punch.

Have a look at this engine, which is identical to yours (75G14 24A)
http://oilyengines.50webs.com/Suffolk%20Engine.htm