Actually that is one thing that I am curious about. With the popularity of IOM in the world, I was wondering why these Model makers don't make more boat that will conform with IOM class rules.
It is very unfortunate in my opinion that the general idea (at least from what I feel from the discussion in this topic) is that if it is mass produced it might not be an IOM.
One thing Martin that you might want to check first is... Does the Voyager have a bow bumper? If not then that can be considered a good indicator that "it was not designed as an IOM" in the first place.
With all due respect to others who contributed to the list, I for one would like to encourage Martin to try making the Voyeger IOM compliant.
For starters, you really would need to make or buy an IOM rig. No you don't need all 3 rigs to start racing, but as Lester mentioned you might find yourself in a race condition with winds too strong for the A rig, in this case you will be overpowered and thus will not be competitive.
I do agree that there is a possibility that your Voyager might not be as competitive as other models, but in club racing and if you want to have a taste on how IOMs are raced, then go for it with your Voyager.
Other items to make sure you are compliant are, overall weight, Keel weight, and bow bumper. Which to me after the Rig are the most important aspects of the IOM class to comply with. I trust there are no carbon fiber in your Styrene/Plastic hull
The others have a great advice too, go to a club near you that sail IOMs and ask them to check your boat out for comliance, if you can talk to a measurer, the better
I really hope more commercial modellers make IOM kits, this will not only lower the entry level cost of IOMs (imagine an IOM that costs the same as a seawind), it will surely help the IOM class become bigger and bigger.
I have blabed enough!
TTFN
Arvin