The only real complaint I have against Blakes seacocks is that the thread for the nuts holding the keeper plate really need to be a MUCH finer thread. You get them nicely adjusted, tap the locking washer tabs into place and then nothing will move.
If not regularly maintained, the cone can seize in place and can be a devil to get out. A long soak with releasing oil can help, but then it can also seem to add surface tension. I have resorted to a hardwood drift and (throttled) sledgehammer to whack one out. The old ones (better material) can be serviced and remain in service longer than you ever expect the hull to last, though the addition of the grease nipple on the later ones is a useful improvement.
Rob.[/QUOTE
The ones I had, on a 1984-completed UFO27, had locking nuts, which I think is a much better arrangement as the tab-washers need to be replaced frequently.