I was also thinking of all the used and abandoned boats here in Michigan ports and storage yards. Most of the speed boats have elecro-hydraulic trim tabs. Had a 18' Sea Ray years ago with those. The trim tabs have to withstand a lot of force at speed. I wonder if one of those might be a solution. Plenty of strength and holding power yet short enough to fit in the push frame easily. Of course a small hydro tank and pump would need to be mounted somewhere in the machine with lines to the cylinder.