Less kludgy.. frame builder or just decent metal hobbyist shop.
The paint can be burned off, around that piece , the steel cleaned up , another stop brazed on,
and then some touch up paint re applied.

you could use a shifter braze on then add the cable stop/ cable adjuster/ shift lever boss cover
common to so many bikes, the boss itself is much more rugged,
surface to braze it to the frame tube is much larger.