Jedi,
I don't know if you've made the drive yet, but, yeah, usually around 1.625".
The biggest thing to do is make sure you're familiar with how all the controls work. Scratchy pots are easy to spot, but you really need to know what all the knobs and switches do, in order to evaluate the bass's electronics. (You may already know all this. If so, I apologize...) OEM replacement parts are getting expensive, so any serious electronic or mechanical flaws could be deal-breakers.
I'm not aware of any "known" issues, although one local tech swears that the T's were known for having less-than-stable necks. I haven't seen much of this firsthand, though.
You didn't say what year this bass was, but if it's an early one, make sure you're comfortable with a slab body. I prefer the contoured T-40s, but I also own a Ric 4003, so what do I know...?
Happy hunting!