Hi Mark, i'm afraid it's a total loss, that is: this version is the worst one they ever made: because of aging the conductive layer comes off.
i've seen many of them 'fixed' with silver paint but also that comes off after some time, makes a shortcut, so the thing won't work again and drain the battery.
The nicest version is the one with real contact plates, this one is fixable because one can exchange these plates (with a donor), is a bit like the old thick (chocolate bar) remote.
the second best is the one with the double layer foil with the switches in it, these also last long.
As far as i know you can't get the foil with the dots anymore...
I think the cheapest option would be to get a cheap ugly but working one and exchange the inner bits (hoping it's a different version, from my experience most of these are with the double layer foil...).
Oh, if anyone really wants to knock himself out: i bet it's the cheapest bit of B&O ever: get 4 new rubber feet for it, cost 25 eurocent each and can be ordered via any dealer :):).