Great looking machine.

Unfortunately I'm more familiar with Mills and Jennings machines. Our expert is very busy now, and out of his home state but I'll PM him to see if he can chime in.
Value of slot machines really depends on demand and sometimes location, at least with more "modern" machines.
For right now, try posting on
www.coinopcollectorforum.com with your questions and photos. Sadly one of their best members passed last year, but hopefully someone there will reply. That forum is specifically for antique mechanical machines, where NLG is primarily for machines from the 70's and up. If they ask you for a code, send me a PM and I'll give it to you.
Hope this helps!!