Gotcha beat! The fuel sender floats on Fat Albert the Apache are 1956
vintage, the stencils clearly visible when we inspected the tanks 2
years ago and replaced all the cork gaskets... And the rubber tanks
look like new on the inside with the yellow stencil looking like it was
put on five minutes ago... Amazing... The best hypothesis I can make is
that the plane was always hangared other than on trips, with the tanks
full, or nearly so, much of the time...

That the new floats are lasting as little as a year, is criminal, but I
don't know what you can do about it given FAA regs, etc. well, I do
know, but it means you would attach a non certified float on the end of
the sender arm, not put it on the log, not notify the FSDO, etc., and
we all know you can't do that, so don't even think about it

Denny