If you have a 235, this number should begin with a letter.

The first letter is the plant (T = Tonowanda F = Flint, etc) the second is the month built (01 = Jan, 02 = Feb, etc) the third is the day (1-2-3-etc) then possibly another letter.

Or....

The letters should appear at the end of the sequence.

Could the last part of your number be "F 55.." and not 7 55?