I am all for reverse engineering a part when it makes something useless without, but have you tried the obvious route first? that is ringing up inverter fusion and asking them if you can buy just the replacement encoder as a spare part. Some companies are complete a***s, and some are helpful and will support you for goodwil and reputation. If they dont support this any more, its worth a quick ask to see if theyll share any info about the needed part even if they wotn supply.yes the knobs