I'd just buy a replacement hp 750 body from Holley or Proform and see how it works.

What is that in the arrow anyway??

You actually can tighten the boosters a bit with the booster install tool, provided they're not too loose.
If it was a race car running race fuel, you could also JB weld where the booster comes into the Venturi........ But it just gets soft with long term exposure to ethanol.

Another even lower buck option for main body replacement is to see if you can buy a used stock Holley main body from someone who swapped theirs out for a Proform unit.
Cut the choke tower off, blend it in........ Should work okay.

You could also send to a carb shop to have the boosters replaced.

Oh....... And I don't consider that an "old school" 830. That's a HP830.

The old school ones had choke towers on them...... Like number 0-9380.
There was a downleg version too...... Can't recall the number though.