I've used a few regular size Reynolds HTs now and they're all exactly 34mm ID. No reaming required but sometimes a bit of loctite is. Not really a fan of this but since I don't own the reamer the right size it actually works out quite well for me. The 44mm ones in the catalogue say "43.95id" which I'm sure is exactly what they are.

I'm thinking of making an improved jig and plan on aluminium cones for everything now that I have a minilathe. But I won't make any big enough for MTB HTs. If/when I do another one of those I'll probably use the wooden ones I made the last time.