Pearson 30 questions...any answers?

[rockhopper]

1978 Pearson 30 OEM through hull sizes (hose I.Ds. are the same):

Engine exhaust 1-1/2"
Cockpit scuppers, port & stbd 1-1/2"
Engine raw water 3/4"
Galley sink drain 1-1/2"
Head flushing water 3/4"
Head sink drain 3/4"
Head (toilet) overboard discharge 1-1/2"
Holding tank overboard discharge (macerator pump) 1-1/2"

So I noticed a couple of weeks back more things they must of changed. My head sink drain I believe is 1-1/4", bought 3/4" without measuring it only to be surprised. I'm guessing the 1973 didn't have a holding tank for overboard discharge or perhaps someone removed it. My head leaves and runs to an anti-siphon valve I think it is and then runs to the thru-hull with no pump. At some point it had something electronic on it because there is a switch panel to the right of the head, perhaps that was the macerator pump and it went to a holding tank. As there is a switch that has something about a tank being full and to either hold it or flush it.