I did it using two C models and a Revell H in 35th/32nd so I could come up with a good 35th scale D/H model. It works, but its an incredibly difficult conversion. In 24th, unfortunately, you could do it, but you don't have the D/H parts to steal for the tail and forward cowling, nor the rotor head to really make it accurate.
You'd have a lot of scratchbuilding with a lot of compound curves. It CAN be done, but it will be really hard.
Jon