Hi Frode and welcome.
Looking at the photographs of the car - the bulkhead looks very corroded, you can buy stainless steel ones but it involves a lot of work.
The area below both doors appears to be corroded quite badly from the inside so the Ash frame has been or is wet and possibly rotten. A reasonable quick guide is to check the security of the small nails holding down the aluminium plate on the door entrance. A good firm grasp of the leather covered section in the same area will give you a good indication also. Personally if I were buying one of this vintage I would need the covering of this section removed for a close inspection of the metal corrosion and the rot to the frame. Ash frames or parts of frames can be made by yourself or supplied by companies such as Harpers in UK.
Impossible to judge the condition from photographs these are first impressions only. Looking at the Chassis and particular attention to any joining section areas is important as a chassis change is a lot work. A ramp inspection with someone in your Morgan Club would maybe be a good idea.
Good Luck
Last edited by 4/4sportsfun; 31/03/13 12:16 AM. Reason: +