Appia bits are easiest to find. A much simpler car than an Aprilia as well. About the only reason to chase Aprilia bits would be if determined to have a prewar car such as to compete with the VSCC, and even then every chance they wouldn't have it.
David
I'm not too fussed about authenticity or attending historic events, it's mainly for the fun of building it and then for bombing around country lanes pretending I'm a racing driver cum constructor. I'm not a big fan of most old British car parts and would need some more 'elegant' and obscure running gear.
Good point regarding the Appia bits - I'll consider those if I do go down the Lancia special route. To be honest, you've done such a good job of diverting my attention towards etceterini type specials with FIAT bits that a Lancia special is looking less and less likely