IMHO, please do not take this the wrong way.
It is great that you all drive so much that having a cupholder is a concern.
In my experiences, no coffee, no food, smoking etc. happens in any of my cars (except my 140k 96 Jeep).
Having a cupholder is a bit like having a CD player, sub woofers and heated seat. All of which is not in my association of driving a fine automobile.
All of your cars are fine automobiles, which someone would give pretty much anything to spend time in. Hearing the engine, the gears mesh and exhaust tone is such a satisfying experience for me, that a cupholder becomes un-thinkable.
If I had time to drink coffee, talk on a cell or wanted to listen to a CD, then I would feel quilty to own any one of my British cars. For me it defeats the purpose of being able to listen and feel the machinery.
Also, if I had the time to do any of these things then the car would not be satisfying to me. The reason that I own/drive these vehicles is to experience things that would not be possible in any other vehicle for the same costs that we invest.
These are merely my thoughts, and please do not take it the wrong way, but if Sir John Black, Cecil Kimber, William Lyons, etc. heard that a cupholder was preventing their beautiful creations from being enjoyed, I would think that it would not settle well.
Enjoy your treasures and have fun, we are all very fortunate to be able to share such a magnificant experience.
Patrick
36 MG
59 & 60 BE's
67 XKE
71 MG