Thanks. This is very helpful and making sense. Actually my '87 radius blue burst and red burst are both sitting in the hard plastic type cases (M100C), so from what you're saying this is actually not even the correct case for these guitars
So basically to sum it up,
I think i need to look for the chainsaw case or RG550LC for any '87 (RG5xx, 540R 540S)
For '88-'90 I think I want RG550LC. (RG5xx, 540R 540S)
For 1990-'93 i want RG550LC or M100C (RG5xx, 540R 540S)....maybe M150 for 7xx series?
Correct? (i'm not sure what year they started offering the M100C, based on what i put above i'm assuming 1990). I also noticed some of my M100C say Prestige Deluxe, some say Professional Delux, and some have no badge in the middle.
The exception to the above is the 540p(ii). For this (as you said) I think I want the RG550PC (whatever that is).
I *think* i have one of these (came with my 540p and seems to fit it well). It's basically like the regular tolex case but the guitar fits in at sort of an angle. A pic is below...i probably should have taken the picture with the guitar in it as opposed to empty. Finding more of these i suspect will be a challenge.
For the 540pii (european model) i believe the original case is the one below (looks like chainsaw case but with red piping). I'm not sure if someone can confirm.
So aside from the 540p/pii it sounds like i primarily want the RG550LC or M100C for this era. The one additional question i would have is what is the case in the below picture? It's a tolex case, but doesn't have the piping and clearly isn't a RG550LC (unless they changed them). I have a few of these that came with guitars from this era and I don't know what model it is or for and for what years. I think the guitars that have this case are from around 91-93...so i'm thinking maybe these came a little later?