Hey Scotty T, I only have one RV. H-34 in /48 so..sorry..no spare parts but,if the fairing your talking about is the one that looks like it has a 'step-down' shape maybe I can email/fax a 1/1 copied version (of the actual model piece) that you make a balsa wood copy of; if you know/can vac-form plastic to the balsa shape....i can copy the shape of the tail rotor pieces as well but need to find my micrometer to tell you 'how thick'.
depending on how easily viewing into the cockpit is you might be able to getaway with just taking a piece of /32 solder wire and form it up against the remaining cyclic stick to make a reproduction that's close enough
'Nam -34s were way pre my days so I don't know if these aircraft flew without the doors (to reduce weight and/or just to get it out of the way), hopefully someone qualified will help answer you
Brian