/\ /\ /\ +1 to all of that
I have rebuilt lots of different pumps............
To elaborate on what Nick says, the problem is that the "Hard Parts" Seize and you cannot buy spares off the shelf, yeah, seals etc are readily available from a Hydraulics Supplier, but that isn't the problem, the re conditioners actually strip loads of used Pumps and use the Metal Hard Parts to make up a good unit.
They may get commonly busted up parts manufactured, they also will Machine damaged Castings and fit oversized newly manufactured parts, which they buy in batches..............
Not something the average DIY Guy has access to
If you do manage to find someone who supplies Parts, please let me know, I have 3 u/s Pump Core Units here.
Assuming it was profitable, I would rebuild them and put them into stock, for the next Vehicle with a broken pump
Re the SDS, that's exactly how I bought my first Kit, an owner had sold his MB and had no further use for it, I bought it plug and play