Originally Posted by rideandgoseek

I confirmed with him that the mustache handlebars are the same brand (Nitto) and model that would've come on the Bridgestone XO-1 in 1993 and my guess is that the original owner had them put on when he originally bought the bike or soon after but that again is just a guess.

I have found what I believe to be the original Nitto Mod 165 bars NOS on Ebay

Handlebar Nitto Mod 165 Vintage Clamp 26 0 N O s C C 42cm 40cm 38 5cm | eBay

And here is the specifications page for the RB-1 from 1993. Can anyone confirm that these are correct?

Bridgestone Bicycles 1993 Catalogue page 64

If I don't like the reach of current set up with the mustache bars then I think I'll make the plunge and buy these. Starting to get a bit pricey ($120 for the bars with shipping) but if I can end up with a really nice conditioned RB-1, all original components for about $700 I think I'd be happy. Plus I'd still have the mustache bars to throw on one of my projects in the future.

Just wanna say thanks again for all the input everyone! I'll post some pics once I have it in my possession and let you know how the handlebars are working out. Supposed to have it delivered on the 14th of August.