The Enya 15 shows up quite frequently on E bay and usually is not a really pricey item to buy. In almost all cases the ones that I bought they were in really good condition and some even needed to be broken in they were that new.
Prices are generally under Altech's price for a new one but They are selling the latest version and it is a C/L ready motor.
To Altech's credit they do have all the parts to convert an R/C motor to C/L for the 15 the venturi # is 15321 cost $2.40
The needle valve assembly is part #15220 and Cost $9.70
Shipping is additional.
The Enya is not the most potent 15 of all the ones available ,but it is a really steady, reliable , well made unit that with proper break in and reasonably decent care is almost impossible to wear out.
Oh Altech's phone number is 732-225-6144 if you need to get parts or motors.
Dennis