If you go to Aug 14 - a topic was opened on Careening HERE
No doubt, your boat , if it is similar to the boat in the second picture could be Careened on a suitable beach or ground, tied vertically to pilings or some other strong structure. You could easily have 4 supporting legs made up, if you intend to Carreen often in places without existing structures to tie onto.
The technique needs planning :- Visit the careening area by dinghy, test the hardness of the beach or ground, Check the tide tables carefully - twice! Ask locals for suitability, Check weather forecasts.
The boat in the first picture is in a Shipping Cradle - these are made to tranship boats by flat bed trucks, trains and ships.
Bilge keelers are very common in Europe, many can been seen drying out every day for months on end - especially during winter.
It would not be desirable to add 2 additional keels to the Pearson - It would be a major boat yard undertaking, probably involving the removal of saloon and cabin soles to reinforce the internal frames and stringers. Also the additional drag provided by the bilge keels would certainly slow the boat down. A removable leg brace system is simple and inexpensive.