Broctoon

I have a 1990-vintage Trek 1100 that came with 3x7 drive train and Suntour shifters on the downtube (friction left/front and indexed right/rear). I've switched to a modern compact double crank and a freehub/cassette wheel, with seven cogs and a spacer, so I can still use the old shifters. Now I'm ready to upgrade to integrated levers and a 10-speed cassette. I'm confident in my ability to install some Shimano 105 levers and compatible cassette, RD, chain, and cables. As they say, the devil's in the details, so here's my potential hang-up:

I'll obviously need to put some housing stops for both dérailleur cables in place of the current shifters. I see a few different options available for this. As far as I can tell, they're designed to work on old shifter braze-ons that are a simple, hollow, round stud--internally threaded, of course--with a square section near the base. The mechanism inside my Suntour shifters uses splines for anti-rotation effect, rather than the square base. Therefore, on the right side at least (I haven't taken off the left one yet), the stud has splines about halfway down its length. There are six splines, I think, with one wider than the rest to enforce the correct clock angle. Will this make any difference for the housing stops?

If the highly preferable approach mentioned above does not work, I realize I could always go with a clamp-on housing stop, like manufacturers used on millions of bikes with stem mounted shifters. The trouble with this approach is that I have an aluminum frame with oversized downtube. I think it's 36mm, but would have to measure again to confirm that. I'm not sure anyone makes a clamp-on stop that big.

Thoughts?