I am pretty
sure RML never made or badged a monitor for the 380Z. The
 We had 380Z's at school (heck, that's over 20 years ago!), they had those
 little 9" Hitachi monitors that come in a roughly cubical metal case on
 them. 
 Yup, same here and I've got one of those working as monitor for my
 homebrew wooden cased Nascom II....you need to be able to view pictures so
 you can see it on the website :) 
 
It's OK, I know what they look like. I have one somewhere. I think I even
have a schematic somewhere too...
The common model had an approximately 9" CRT. I think I once saw a
similar unit with a 12" CRT, the case being somewhat larger in all
directions. I think the internals were all much the same, though.
-tony