Re: Looking at a 1974 Pearson 30'
From the pics provided, all that 'weepage' around the stancheon bases indicates severe water intrusion into the deck core. Its 'Fixable' but takes a lot of work.
The pic of the compression post -- that 'black' in the post base is ROT. That C-post will need to 'additionally' have is butt end cut off, a FRG pedestal made and inserted. Does the door into head close? and does the door hardware line up? If not, it means the bulkhead has shifted in its 'tabbing flanges' (because of the previously rotted compression post) ... and thats going to be a 'problem' in realignment - can be done but 'tricky'.
On a lake, an outboard on the P30 isnt goint to be a problem if you can integrate the engine speed to an in the cockpit throttle. This boat has a tiller/rudder so steerage at low speed isnt going to be a problem with an OB, just dont attempt to steer the boat by the OB, use the tiller/rudder, and simply 'take it easy'.