OK John, chime in I will!
When I rescued her, The Red Witch ('79 DS2) had a through-hull pipe that I suspected was what was left of an original Depersia bailer. It had evidence of having threads at one time, but it was so corroded that they were worn down to almost nothing. It did not leak into the bilge, and I just kept it plugged with a stopper.
After one particular experience where having a working auto-bailer might have made the difference between my bagging and heading for the docks on a multi-day long distance "raid" or continuing on, I decided I better "gits me one". So I bit the bullet and forked over the $50 to D&R. Hey - I got no problem schmearing Rudy and crew whenever possible: I want them to stay in bidness as long as possible!
Installation was a breeze: used a hole saw to cut out the old corroded pipe, then just screwed the new unit in. At first I wondered if the fact that it doesn't match up flush with the hull underneath would matter, but I don't think it does. I used silicone liberally while installing, just so that I could take it apart and do it differently if it didn't work. If/when that ever fails, I'll use something a bit more permanent.
It works as advertised, but there needs to be a fair amount of water in the cockpit to "get it going", so to speak. The slower the boat speed, the more water you need, and vice-versa. Kinda like priming an old timey water pump. But once it starts draining, it does so very quickly! Oh, and of course, the boat needs to be flat/level. It won't work iffn the H2O ain't reachin' the opening!
Just for kicks, google "depersia bailer". Use the quotes. Better yet, do your search in Google Images. I was actually surprised that the plastic version took over for the metal one (bronze/aluminum/?) as early as 1972???
One interesting hit I got is this one, which is actually a post card in the guy's collection. Definitely shows the "finger sized holes" you mention David, but I still can't picture how they would translate into a way for water to get into the bilge?
Might have to scroll down a little/lot:
http://books.google.com/books?id=nQv1Yy ... er&f=false