Float Bowl Repair
There are a few suggestions for this. The first and easiest is if there is a crack down the fuel overflow tube then clean it up with some sandpaper or scotchbrite pad and use a soldering iron to fill the gap.
Another is this by Reg. Waiting for pictures.
From Reg in Bristols site
Float bowl repair
A Spare set of carbs had a split overflow pipe on one float bowl
and the other didn't look too healthy either.
I have seen and heard of this problem on a few sets of carbs
and reckon its an age issue, so finding 2nd hand float bowls isnt always the best move.
Some 3/32nd brass pipe from a model shop was used (80pence a foot)
as I found this fits snugly into the original.
A dremel cutter was used to cut the old pipes off flush with the base
and the cutter changed for a narrow engraving tool used to rough up the inner of
the old pipe to help the glue key in.
6mm of the end of the new pipe was roughed up and coated with
petrol resistant epoxy, then fitted into the hole.
(Removing the drain screws allows you to check you havent gone in too far)
After the epoxy had cured, I trimmed the new pipes 8mm above the level of the bowl
the Dremel was very useful here as it allowed me to cut and trim
the brass pipe without distorting it
A pretty simple job really, as long as the epoxy really is as petrol proof
as it says on the box, then I dont see why I should have any problems.
The Third solution LRCXed Larry found by rolling metal and pressing it into the hole after removing the broken tube.