On the pitot pickups, get the teleflex pickups from skidim. They are less prone to clogging than the originals. Drill two holes in the new pickup using your old airguide pickup as a template. Give the screws and holes a good coat of 3M marine sealant and screw the new pickups on. Attach the tubes and you should be good to go. The original pickups are hard to come by and priced pretty high every time I've seen them come up used.
From memory, that piece that you motorbox attaches to is pretty small. You could fill the holes with epoxy putty, reinforce the underside with some hdpe, and some heavy duty washers, then reset your bolts and nylock nuts.
Previous: 1993 Prostar 205
Red 1998 Ski Nautique, PCM GT40, 310 hp, , Acme 4 blade, Perfect Pass SG/Zbox.
Be kind. Have fun.