The inner diameter is 1 and 7/16", so you'll be fine.
The only problem is: there's too much space inside--everything just kinda flops around.
I have 4 Heilands and have designed a crystal chassis just for them. The parts go to the shop Friday, and I should have a completed one by next Tuesday. I was waiting for my TGS blade holders so I'd know how long to make the chassis. You could wait until I'm done and see if you like my work and would like to go in a similar direction.
The design will be different from Master Yoda's, more solid because there's more room inside. I'll be using the design from Vader's lightsaber in the visual dictionary, only a little less detailed. Red LED illuminating a piece of quartz (or crystal...they have lots of that here ;)). It'll also have a recharge port under the MPP clamp. Why? Because on an authentic MPP, the grips will extend over the pommel and make a big mess every time you change the batteries. I plan on using special batteries to save space ;) (there are many advantages to being in Taiwan :D).