Just gonna toss this out there...
When it comes to spending Big Buck$ on "OEM replacement parts" I also consider purchasing a used -002a or -003a Gensets that are advertised as: "Not Running" or "As Is". Some gensets, especially on places like Craigslist, etc., can go for a few hundred dollars & you get everything: wiring harness, fuel pumps, gen head, control box, fuel tank, injection pump, etc. If you were to purchase each part individually your well over a grand plus in parts pretty quick.
Often you can end up with the part you need, albeit used, & if you should choose to eventually get the "donor genset" running you end up with a complete "spares set" or even a potentially working backup generator.
So far, everything that I purchased that was not running or alleged to have run x-years ago were fairly easy to get running. That way, I know every part is good and unit can be used either as a "roll in backup unit" or "parts donor" in time of "mission critical power outage backup needs."
With the -002a & -003a series parts listed on places like eBay have become much scarcer than ~10 yrs ago or gone up a$tronomically if you can even find the part you need.