Bill,
I for sure agree with your last post. Important thing is to recognize what parts go with what setup/mod and IF using a blank plate, one probably should do the drilling. If I had a nice original motor I probably would toss the large baffle and use the tube plate and not do any drilling exactly as you did.
My Idaho RD-18 was partly modified and came with the blank plate so I used the blank plate and drilled 3 of the 4 holes. Too hard to angle to get a 4th hole. I did file out the 3 holes to enlarge them a bit. After all the motor apparently ran with blank plate and not the 4 holes.
One small thing. If you look at my first two slides in the thread, you will see that the 1/8 water outlet hole lines up with the first chamber on the left. That chamber is the poop hole outlet. So if the 1/8 hole is in that position any mod will run water out of the poop hole. Notice the first mod, which I don’t like, moves the water outlet to be in the same place as the RD18.
Other knowledgeable experienced people may draw different conclusions but I think we all have gotten to the facts.
Regards,
Charlie