I picked up my 261 today and I have something like you, Whizzerick. The 261 I have is casting# 3733950 with head casting # of 383513. I believe this head number is for a 235. My 261 also has a tag where it has been rebuilt, so it will be interesting to see if the steams holes have been drilled or not.
Whizzerick, let us know what you find out about yours.
