I've had my 73 Ski Nautique for 10 years now; bought from a guy in Indiana in February of 2005.
I had a bit of trouble with the original motor so I've been building the one pictured below (my first build).
It has been on-again/off-again with more off than on.
7/2015 update:
She's finally running... but not well. I've ordered a Quick-Fuel carb to replace the Holley.
We'll be on the river soon.