I don't think I have ever seen an FEL that didn't have some kind of bucket level indicator. It might be a rod moving within a larger tube, a rod with a V kink on it that rides in a bracket OR just a flat plate on the bucket that you have to gauge if it is flat but they all have some indication of level on them.
I guess the easiest and simplest is the addition of the flat plate on the bucket. Anyone with a level, a welding machine and a little bit of 1/8" sheet metal can fab up and install one of those in half and hour.
I strongly suspect that the OP has one of those on his bucket already or one of the rod type.