New to me Sunco 12-155R

[JackCross]

I am a newb and just want to sew lightweight motorcycle seats for myself. I'm tall and like to make my own seat modifications and I have been using a stretchy fabric as seat covers but would like to start working with lightweight leather. From the wisdom I have gathered on this site I started hunting for an old walking foot machine and just picked up this Sunco 12-155R. Google searches turned up nothing but a google image search took me to Rex and Juki machines that look similar. I guess this is a Nakajima machine? The numbers in the pics are all I can find. There are no numbers stamped on the bottom that I see. 
 

Can anyone tell me anything about this machine? If I was trying to find parts can anyone tell me what more common machine I should look for? I'd love to have a manual as well. 
 

thanks in advance for all your shared wisdom. 

[AlZilla]

So, I know nothing about your machine, but I'm always curious to learn. So, I poked around and I think yours is close to a Rex 11-155R.

Here's a google link that will return quite a few hits right back here at this site and may help:

https://www.google.com/search?q=Rex+11-155r+site:leatherworker.net