That should be possible, however as you have found out it's more a matter of locating who will sell/order them ;)
If i recall right,
Did have one...again if i remember right :D
Also maybe try calling perego...
ETA: they only seem to have the caravel frame...
Now you could also try
She too only lists the caravel but maybe able to order the pram frames.
~Pamela Mom Of 3