My story is similar but on a Seneca.
I do not find the single engine control of a Seneca an issue.
Well it is and it isn't. The Seneca 1 is comparatively an affordable twin, but a very weak one. It is true that you really cannot creep below the blue line and have much hope of maintaining a climb (however slight) in normal conditions and the sort of loads one would associate with a decent run to Europe (what one would buy a twin for?).
The Seneca III performs much better, but is much much heavier on the rudder and can be trickier to stabalise, but not difficult when you're expecting it! E even the mighty Seneca III, as I found out during my IR test, with a decent fuel load and two on board will not climb OEI (one engine inoperative) at 600 AMSL and 30 deg C. Something you are likely to encounter on Southward forays during the summer.
but the 70s charm - a friend described it as like an old Ford Cortina
I know what you mean, there is a certain something about that era.