have you tried using the old 2.0 stuff in the 2.5?
east coast sabers on youtube has done a pretty extensive tear down and review of the 2.5, maybe that would help you.Parks / Korbanth Graflex 2.5 Review & Overview - YouTube
says the grenade (chassis) section inner diameter is the same, just now its in 2 parts and doesn't look like a luke ROTJ grenade section anymore.
oh and that the slot for clamp card buttons no longer goes all the way through.
other than that i like the changes they have done. ironically, i never seem to get a saber when it comes out but i was able to jump on the 2.0 no problem.
now i feel like if there was ever a time to sleep on a saber, that was it. 2.5 seems better in almost every way. (better circuit card, red buttons, bunny ears correct length, no funky finish on the clamp)
anyway i hope you find something. i do see the appeal for a 1" blade with neopixel becoming more common. gotta admit I'm tempted. even after watching GCS sabers "what you need to know about neopixel" vid... the price is the only thing holding me back.