Hi
While building the Rider Ericsson Engine I did not like the looks of the pump. It really did not look all that much like the original. I had always wanted to try carving out a casting so here was my opportunity. I need to thank George Britnell for some advice and encouragement. I had a number of pictures of originals and saw there were several variations. I picked one that was not too complicated for my first go at this. I had to guess at the dimensions. The first picture is the pump I decided to model. The second is the block of the 6061 I started with and the last is the pump. I put draft, drain hole, working primer, and square bolts and nuts to get close to the original look.
I posted more pictures and some details over on my build sequence for those who would like to see how it all evolved. It took me about 4 weeks including the drawings. Here is a link to the page that has the start of the pump build about 1/2 down the page.
http://www.modelenginemaker.com/index.php?topic=3441.135I see that Meyer's 3" pump has a pump casting.
Bob