First of all,welcome back.I hope you stick around and offer well reasoned comments on other threads;sounds like you have the experience and temperment to so.As Dave noted,I think we need all of that we can get.
As to your pump,very nice work.Out here in New Mexico,not really farming country statewide,that pump in not all that common.Since you asked for thoughts,I'll tell you that out here the pump would go for about $600 -$800 if you found a guy with a nice restored JD tractor to go with it.I say that because back when I was doing old tractors,including JD's,that is about the range they were thinking about.Anything much over that and they will spend more for a Tok 39 or something similiar done up in JD that they can put a pop globe on.Best of luck.