That's really helpful.
OK that one did inspire an off-topic digression though. (But this is after all the "off" topic, or as I personally call it, "Diarrhea of the Keyboard". (You know, the phrase "Diarrhea of the mouth").
You know those drive-through liquor/convenience stores? I've always joked they promote drinking and driving, but supposedly not since they just stuff it in the trunk of your car or bed of your pickup. But that's useless if the back seat folds out; you can access it from inside the car!
Have you gotten the other T17 yet? (The one you're keeping).
Keep an eye out for replacement lamps; my understanding is that manufacturing is now discontinued and has been for a couple years already (Wow, time flies!). Even if they're pricy, they may be worth it.
F90T17 lamps are 5 feet (60 inches) long, right? I suppose if nothing else you could convert yours to F60T12 slimline or HO; at least those lamps are still in production, so in theory they're pretty common. With HO you might even be able to somehow rig it as preheat to make it seem more authentic.
It's funny you should mention this today since I was just randomly thinking about F90T17s earlier today and how rare and relatively valuable they are to collectors. I don't have any, have never seen any in person (That I can think of anyway) and don't anticipate ever owning any fixtures, lamps, ballasts, or starters for them, and and honestly probably won't ever actively look. BUT, if I ever found anything F90T17 I'd probably get it, not so much for myself but for other collectors like you; for example lamps are useless without a fixture but I'd strongly consider letting, for example, you, having them for the cost of shipping or in a trade or something. (Praying of course the postal service doesn't destroy them in shipping).
If you ever have to transport/ship fluorescent lamps long distance (Case in point, out-of-state sorta-move) I can suggest cardboard mailer tubes. I transported a relatively rare, valuable, collector's-item lamp that way with success before. (It was a "Westy" F20T12/CW that was totally Philips/Norelco in design, right down to the silver/aluminum endcaps, cathode guards, etc; there is nothing truly Westinghouse about it). I took the remnants of a couple cardboard tube mailers, spliced them together, (Cutting one in places with scissors so it would "bend" into the other one) then inserting the lamp, taking other cut-out pieces of said tube mailers and stuffing them around the endcaps, then putting it in a suitcase with clothes on all sides and hoping and praying. Needless to say, it made it in (literally!) one piece from California to Alaska without incident. Although I do wonder what the airport security personnel thought as they X-rayed my suitcase...I think I even had the "inspection notice" in my suitcase afterward.
About six months after that I went down there again to clean out the house after my mom passed away. Since I also went to the same ReStore the Westy silverender came from while down there just for the fun of it, (Although I did get a couple 8ft slimline ballasts for my godfather's woodworking shop lights, one of which I helped install the same day), I should have looked for some 2" PVC or ABS pipe to cut down to 48" sections and stick the '88 Philips (Norelco-made) F40CWs from that house in to ship up here. But I did not. Granted, I also left many other non-lighting things behind I wished I could have taken that were even more valuable to me.