Welcome to the forums. I'm guessing this model must have been made to compete with the Dave Scott Ironman. Nice bike, though I have a few other "major issues"
:
1. Position of those bars/brifters. Please tilt those down a bit.
2. Why isn't that chain sitting on the cogs? Looks like you are trying to cross-chain? (Avoid using big front chainring with largest rear cog, or small front chainring with small rear cog.) And some of those cogs are starting to chip. Perhaps time for a new chain.
3. You are bound to scratch your frame leaning it against rough metal poles like that.
From previous posts, I understand Shimano brifters are not usually repairable (unlike Campagnolo). I've heard people tell tales of brifter resurrection after a spray with WD-40 while moving the lever. Replacement brifters can be pricey. If you aren't trying to keep it original, a less expensive option might be Sora brifters.