Not everyone that sells reel seats offer very many choices in reel seat I.D. Some, like REC, do however and you can custom order a reel seat to the ID that is appropriate for your needs. Reaming to a larger size so that you do not need tape or anything to shim with is ideal, just be careful that when you do ream, that you go slowly as the insert can crack as a result of the efforts.

I like a snug fit of the reel seat to the rod blank, but not so snug as there is no room for the glue that I use. Its a little tougher with graphite or fiberglass as there is only one element that you can impact and that is the insert itself. With bamboo, one can also do some work on the butt of the rod to bet a good fit.

If you go to REC.com, click on the reel seats and you can see some of the sizes that they can custom machine the id of the inserts.