Actually, just found the datasheet for the HEDS encoder, and they were only available in single ended output.
Probably best to remove it, measure up the dimensions and see what you can find in a similar size, as space looks at a bit of premium. Plus I'd guess by the setup, and the datasheet, it's a hollow shaft encoder.

US Digital would probably be the option involving the least amount of modifying. Something like an E5 or E6 depending on shaft size - https://www.usdigital.com/products/e...emental/rotary