Hi Mike, I have been up close to your newly acquired Sipp multiple times over the last 20 years.
It is a 1/2 hp Sipp for certain. It is 23.5" long and has a 1.75" bore X 3" stroke exactly as described in the Sipp Catalog from late 1800s and early 1900s. While your governor and water pump are not original Sipp parts, they are both wonderful examples of period correct hardware that was most likely installed by the original builder. I had located a Sipp with a similar governor some years ago in north east Ohio but the family was not interested in letting it go.
You are to be congratulated on a very fine acquisition!
Gil
ps: If you need a copy of the Sipp catalog, I can e-mail it to you.
@RedRyder, thanks Gil for the valuable information, and for offering a digital copy of the Sipp catalog; that will be very much appreciated if you can.
I will send 2 separate catalogs to you, Stoker, Nick and anyone else who wants them.
One was copied from an 1895 Sipp Catalog and the other may have been a tad later.
The 1895 catalog shows their smallest vertical as first introduced on the last page of this catalog.
The slightly newer catalog shows the small vertical in the front inside as their new offering. While I have seen several catalogs, this is the only one that shows a complete Sipp 1/4 hp steam plant on a cast iron base.
Gil