Re: puddle drain WOW!
the major difference is the powerhead does not look like mine it is a figure 8 style the and all the models I see have a rectangular shape.
If you are referring to the shape of the fuel pump (figure 8 style) and you have a model 1251x8c, that's what you would expect to see. Rectangular or square fuel pumps weren't used until the mid 1990's or so.
Doesn't matter what type of recirculation cover drain valve you have, reed, screw, brass fitting etc, as long as it works, I wouldn't worry too much about it. They all do the same thing.
If you can post some detailed pictures of your block, ignition system, flywheel, etc. we might be able to tell you more or less what year power head you have.
I run across a lot of motors where the power heads or parts have been swapped out from different years.