The pump gets some push-back from the shock when the air valve is opened, until the pump starts to build pressure; the pressure on the gauge has always dropped a bit when this happens, If the shock has sprayed some oil into the line, it will come with the air through the valve, assuming it does push a bit of oil into the line, I found a post, not sure if here, from someone who removed his shock and laid it down horizontally, and a small amount of oil dripped out. He was assured this was normal, which indicates at least some oil can come out of the shock.
The man who mounted the valve and pump tried his best to find an better location, but ended up with the pump mounted just above the transmission, in front of the alternator, and the valve under the rider's seat, in front of the battery. I can't find any place else for either. I can link to the write-up on the Valkyrie forum, if you care. I did, however, attach the air line out of the pump so it points up towards the tank, forming an inverter 'P' trap, which may help block any oil flowing from the valve. It doesn't take much oil to fill the gaps in the desiccant tank, so I don't think it was more than a few milliliters.
I was able to dry the desiccant in the pump I found on eBay, but couldn't get the oil out of what I had. I even tried soaking it in brake system cleaner, but it stayed brown. I have the same size granules from a shop air dryer, they just don't change color, which I put into it. I added an indicator card visible through the window, for inspection.
One of the O-rings I ordered arrived today, so fingers crossed that's all I need. Someone on the other forum suggested that there might be a rebuild kit for the pump, but I can't find anything.