Ingenious, but that doesn't explain the "P". The answer is a bit more recent

Wooden
Propeller on the front?
P for Pickersleigh Road, where the 70th Anniversary steel framed Plus 4 left the factory?
Below is my satirical version of Morgans Plus-4 70th anniversary press release:
https://www.morgan-motor.com/press-...-roll-off-the-line-at-pickersleigh-road/[satire]First limited-run Morgan Aero 3 Wheeler 101st Anniversary Edition models roll off the line at Pickersleigh Road1st January 2021
• The first Aero 3 Wheeler 101st Anniversary Edition models have completed build at Morgan’s Pickersleigh Road factory in Malvern, UK
• The 101st Anniversary Edition model commemorates the end of production for Morgan’s steel chassis, which has underpinned the 3 Wheeler since its inception
• Production of the Morgan 3 Wheeler Aero was introduced in 1920, making 2021 the model’s 101st anniversary from it's inception.
• Just 20 101st Anniversary Edition Aero 3 Wheelers will be built, all of which have been allocated to customers.
• Each Aero 3 Wheeler features an individually numbered plaque, as well as an artisan hand shaped ash propeller at the front.
• 101st Anniversary Edition Aero 3 Wheelers will be painted in Capt. Albert Ball's S.E.5 WW1 fighter plane livery and come with a host of exterior, interior, and convenience specification upgrades such as a timed machine gun which fire food pellets at rouge pheasant who patrol the lonely lanes of the Yorkshire Dales.
• For a short period of time, the Aero 101st Anniversary Edition 3 Wheeler will be built alongside the all-new Morgan 3 Wheeler B-Type, which is underpinned by the CX-Generation bonded aluminium platform.
[/satire] 