I think the monitor is a standard RGB monitor. I still have one that works with the early Commodores.
I learned at a college flea market a couple of years ago some interesting info. I noted that several people wanted to buy the early commodore and atari computers. I found out they were using them for Ham radio answering machines, sorta like we have for our phones. I am not sure how it works but there are some here that can explain it. They are still in demand and at a good price too.
Bebop