Glenn
If you you do all your own maintenance on your M3W and the Jeep, then the pre-war 4/4 Series 1 should have no greater challenges (except perhaps for availability of parts and spares). If you need to use a Morgan service agent I would comment that you should select carefully , not all agents are well versed in these early 4 wheelers. They use a lot of fittings which are getting on a bit, and many mechanics do not even possess the correct spanners!
The 1939 car would be a Standard Special engine I think, which is fine, not sure if the gearbox is Moss or Meadows , but either way there are specialists around like JB Sports Engineering, who are very good (and can look after the rear axle as well)
As ever it will be the condition of the car which should answer whether it is a good idea. If it has been "restored" you need to know who did the restoration , when , and what parts did they replace , and which did they leave as original.
There are many experts on these early models Bill Hughes, John Merton (in Oz) to name but 2, I would ensure that you talk with them about anything that puzzles you.
