- it had to be in service in 1951 (date of first appearance in Biggles Works It Out)
- it could be armed with guns - Marcel said in Biggles Works It Out that he planned to put his guns back in and he actually fires them.
- it could carry at least 2. Marcel gives Ginger a ride in Biggles' Combined Operation.
Based on these features, the only Morane which fits would be the Morane Vanneau, with variants designated MS472 to MS475.