Tire size questions (yes, this thread again)

Hi everybody. Sorry to dredge up this topic again, but I need confirmation before I spend any money.

I've got a 75 CB750 in some boxes getting ready to be a whole bike this spring break. One of the last things on my list is tires, and I'm a little unclear on what size is right.

Now, it is a 75, which came with wire wheels, but I plan on running a set of Comstars that I got from user RicerwannaB. He pulled them off of another SOHC CB750, but I'm quite sure that they were not original, given that it wasn't a SS model.

So I can't just type "CB750 stock tire sizes" into the google machine and be on my way.

What I've got are a 2.15x19 front and 2.5x16 rear. Currently they're wearing 100/90-19 front and 130/90-16 rubber in the rear. Is this correct for the rim sizes, or did a PO put on a way too fat tire to try and look cool?

Thanks!

Those are the stock sizes for that wheel, you can go up to a 110/90 on the front if you want a larger wheel there, not sure on the back though