I have been busily working on 3D versions of pumps. It is an expansion of the work I have done on my Subs, and it is a great system. If you know someone with a 3D printer, you can get the full pump for $10-15 including the subtech valve. If you have no idea what I am talking about take a look at my videos.
You can see these on utube but it is much better on the website as the downloads are there. All free! I have updated all the lathe made valves and pumps I use as these are much better.