no worries Damo, I only see 2 options, to plug the bush holes and re-drill but you need a special drill bit as the bushes are tapered.
The other option is to glue the bushes in, which will be the easiest option, but if you ever have to refinish this bass they really need to be removed. There are some cool methods to extract the bushes.

Be interested to see if any other ESB-4 builders had the same problem.

you could also expose more bare wire for the earth wire and wrap it around the bush may make it tighter in the hole