I believe one of your boats is this vintage model...
http://www.greatplanes.com/discontinued/gpmb1001.html
The Kyosho Jet Stream 800 is self explanatory.
I am pretty sure the purple boat is a Prather Off-Shore Deep-V. I believe Prather is now out of business, but the parts for the boat are really not too difficult to come by.
Prather made some of the best fiberglass hulls back in the day.
In the case of the Blackfoot, I think they are now making the Blackfoot 3 or something, and its parts are probably not that interchangeable. I think they made a lot of design changes over the years with it.
As for the Clodbuster, it is one of the most popular RC Trucks ever made (I own two), and parts are readily available to make it into all kinds of crazy beasts.
Here is just one of the countless examples...
http://www.clodparts.com/products/chassis/7.html
If you wanted to sell the outboard motor off the purple boat, or even the whole boat, I would be very interested. I really need another RC boat like I need a hole in my head, but I have never had an outboard motor, and really want to play with one.
Got "schooled" by member shawn k on May 10th, 2011...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...