...You would think, but I have a 3-page catalog that just lists specs and such. There's no long descriptions or anything. And the header says "Roadstar Deluxe". Underneath that it has the first RG550's (no pickup logos, matching headstocks) and the RG440, 430, 420(no pickguard) and 410 (also no guard) They all have Edges. Then on the next page under the header "Roadstar Standard" it has the RG250 & 240 (no guards) and 140, 135, & 120 (all with guards) They all have powerocker trems.
I'm not saying it makes me right, but it seems that they denote the Deluxe's as having the "good trems" and it doesn't conflict with the info in those other catalog pages. But not all the deluxes had binding or burst finishes. The 525 has rounded edges and I have one pearl white like the catalog, and one "purple haze" from the year before with the Pro Rocker trem. And technically the first 550's were all part of the Roadstar Deluxe line. Its just that later the dropped the nomenclature and went with just "RG". The 3 pager I have also shows all the RG's with uncovered pickups, so it's clearly after the 1986 catalog. But it seems '87 was just a bunch of inserts and sheets because I can't find an '87 full line catalog anwhere. I'd love to see one if it exists. But this can't be '88 because it conflicts with everything in the '88 full line catalog. Now with a name like "IbanezroadstarII" I'd be a fool not to defer to you in this case, but maybe you can shed some light?