I know this is an old thread, but I'm about to try to make the exact same handles. I was a little worried about getting the threaded insert into the the little table leg. You think it's worth it to get different inserts?
Also, is there a gap in your block of wood and table leg? I was thinking about either going your route with the T-nut or putting a threaded insert into the wood block so there won't be a gap.
Did you find there was enough room to write your beers on the blocks? Assuming the ones you got are the same size as mine, I thought they might be a little too skinny, but judging on your picture it looks like there was plenty of room.