Interesting post. Just thought I'd add a few cents worth of input:
On the one hand, Greco were really conservative in terms of Strat finishes. The standard catalog models were usually available in 2- and 3-tone burst, black, white and natural. Some exceptions apply, like the stained violin burst used on 500s and 600s in 1978, and the short-lived Fiesta Red/torty 1979 SE500PR (a Peter Frampton sig model that nobody apparently bought).
On the other, Greco had a custom shop-like operation going from very early on (since 1972, according to one catalog) and so there are lots of custom and short-run store order guitars around.
Personally, I think your blue guitar is a refin. Custom or short-run guitars tend to have more differences from standard than than just the colour. As I recall, I've only seen one factory blue Greco SE, but that was a "LAOX Original", part of a 1978 production run for a store chain, but that was a metallic finish and also featured a Fender Mustang-style racing stripe.
From what I can see, the Tokai you linked to is not a 1982 as the seller stated, but a fairly early 1978, i e from the first full year of production. It's got the early small, blank neck plate and a 7-digit serial neck stamp beginning with 8. To me, the pickups look very much like they're out of a Silver Star CBS-era copy, not a Springy. Most were unstamped (though S and H are also seen) and the black and blue wires are typical.
Greco SE headstock decals... you basically need to make an Excel sheet to track all the changes through the years... but the large cap Super Sounds moniker guitars are either 500s or 600s. There are two versions, one all-black and one with a bit of gold trim. As I recall, the latter was initially just 600 and then came in on 500s as well. Don't remember exactly when, but during the last couple of years of the 70's I think. Then there are the small-cap Super Sound (no s) decals, used on pre-CBS copies from as early as 1976 (on the SE800)... suffice to say that it's complicated.