Yeah, I think you got it...I posted questions about this topic a long time ago, and pretty much figured out the same things. As far as matching stuff, good luck; it's alot like the tweed to blonde to brown to black tolex changes of Fender amps in the late 50's/early 60's. Check the link to Rich Briere's website(at the bottom of the main page here); when you get there click on "Sunn part 2"---it's a reprint of a history of Sunn amps featured in Vintage Guitar magazine a couple of years back. You'll find more info there. The grille cloth with the stripe is from the short-lived late 60's Orion solid state series.