We've got Kevvo set up on the back of the old barge with turning blocks and bungy cord for the tiller lines - several years of playing with it all and there don't seem to be any improvements left. Except - we have always used 6mm sheathed braided line for the tiller lines and these have always chafed in two places and they tend to jump out of the sheaves on the actuating arm when there is violent movement. This time we are using 3mm unsheathed plaited spectra and it works beautifully. Minimal chafe and because it is so skinny it doesn't jump out of the sheaves as long as the bungys are properly set. Found a roll of the stuff in Dave Carne's back office in Falmouth and thought it worth a go. Breaking load about 600 kg - easily enough for the old Kev.
The first half cup of water from the watermaker each time we use it is always brackish from the back pressure in its guts. Read the instructions! I'm sure they shows the proper set up with bypass valve etc but we haven't got room for all that stuff so fill a cup before putting the tube in the first bottle. It's taken us years to work that one out.
Salad oil, cooking oil or even yer extra virgin is great for keeping the marine version of the old one hole dunny working smoothly - if you have a can of sardines in olive oil, pour the oil into the porcelain and next time you go, you will feel the difference in the pump action. Otherwise, a tablespoon every few days keeps the pump barrel slidey.