I don't know if Peter Scrivens subscribes to the forum, but he has sorted out the problem for at least one of our members. I believe he uses Oilite bearings ( a sort of oil infused sintered bronze) and a stainless replacement shaft.
Although originally fitted with only a manual winch keel lift system on my Parker 27, I fitted a homemade hydraulic lift system which has worked well these last two years. It comprises a 400mm stroke hydraulic ram placed vertically along side the keel box in the fore cabin. Attached to the ram which is pointing upwards, i created a hanger for two Barton 3 series blocks. at the bottom, the ram sits on a stainless cage which has two more Barton 3 series blocks and an attachment eye for an 8mm Dyneema lifting strop. the other end of the strop passes through two turning blocks up near the coachroof top, so that the strop passes through the side of the keel box and attaches to the keel about 150mm down from the top of the keel. I therefore have effectively a 1:4 reverse purchase, ie when the ram travels 400 mm, the keel moves 1600mm. the hydraulic pump with built in reservoir is positioned in the void under the cockpit wherein also lives my start battery and Eberspacher, there being a reasonable amount of space which cannot be utilised for much else.
The keel is raised and lowered by a momentary action on-off-on switch located in the start panel housing. It takes 40 seconds to raise and about 35 seconds to lower, and for single handing is an absolute boon. To hide the hydraulic ram, I made a 1/4" teak faced ply housing with teak corner moulding, it is approximately 4" x 4". you would think it had always been there, it is so unobtrusive and blends in well with the teak faced bulkhead that it sits against. I had to get the small infill cushion modified to fit around it, but everything else I made myself, including the 5mm thick stainless hanger and cage which I then got my local stainless steel fabricator to weld together for me. If I recall the total cost of the installation was under £500, the most expensive part being the hydraulic pump which I think was £185 from a company called Hydra Products, who are also exceedingly helpful. If you tell them what you are trying to achieve, they will put together a pump to fulfil your requirements. My pump draws about 1/2 amp to raise and about a 1/4 amp to lower so power consumption is very reasonable. When running, the pump draws a maximum of 27 amps but you are using it fo less than a minute at a time. To deliver that amperage, the switch activates a double relay which I bought new on Ebay from a company that makes them in the USA, I think it was £36.
I was originally going to fit two limit switches but eventually found that I only needed a limit switch on the raising side, you can hear the keel hitting the bottom when lowering and also the note of the pump changes, the lifting side needs a limit, as the actual keel lift is a total of 1570mm so you need to stop it from travelling the full 1600mm which the the 1:4 purchase on a 400mm ram will achieve. Rams seem to only come in 50mm increments so the next smallest would have been a 350mm ram which would not have been long enough(1400mm @ 1:4)
The keel on a Parker 27 weighs about 200Kgs so the ram is effectively moving 800Kgs (1:4 ratio) but if my school era physics is correct, the pulley blocks are each only carrying 200Kgs and are sized accordingly. For a Parker 275/285, I believe the keel is 400kgs so bigger blocks and a more powerful hydraulic pump will be required (the next size up for both items as I recall when I researched it for a friend). The ram is capable of lifting about 2 tons or more, so is fine.