To be honest I like the 396 and miss that wee box of worms.

That's a better solution.
With hindsight, the adhesive on the reverse side of the tape may not make a good electrical contact with the pads on the Zumo.

Edit - UPDATE

Well I tried it with aluminium tape, cutting a small circle out with a belt punch and then covered it with a approx 8mm square of ...

I did think about that but you stand a good chance of cooking the pins inside the plug.

If you are going to do it, I would recommend removing the rubber gasket around the pins before starting to solder.
Using electrically conductive paint is simpler, although you have to periodically renew the ...

I have been making very slow progress with my connection problem.

I spent some time last week making a new plug out of Milliput modelling clay and plan on using a hobby drill to make a cavity to house a set of pogo-pins to make the new contacts.

I make an interesting discovery, while trying to get ...

I had an old Garmin USB power supply cable and tried to take the cradle pin plug apart and for those of a curious nature...

The pins are set into a hard plastic base and the contact pins are set into a soft plastic shell, which fits into the cradle and is secured to the cradle with a single cross ...

A 200 mile run yesterday and the Zumo had an uninterrupted spell of power with a third layer of conductive paint.

I didn't remove the Zumo when I stopped for lunch, it will be removed tomorrow when I take the bike to work, so I'll be curious to see how things go on the road home tomorrow night.

I got the opportunity for a 50 mile ride this weekend, testing the painted contents on the Zumo as I went.

The results were a mixed bag, it worked, a solid connection for the first half of the run. I removed the Zumo when the bike was parked and the GPS had intermittant contacts for the second half ...

I got the conductive paint last week, the contacts were thoroughly degreased and painted then left to heat cure and that is as far as it has gone.
The weather here has been bitterly cold and wet so I'm desperate for a good day to get out on the bike and give it a try.

I am also giving it serious ...

With the intention that this may be useful to anyone else suffering a similar problem...

I ordered up a set of pogo-pins with the intention of making a new power connection for the Garmin cradle and then had a good close look at the cradle plug on the three old sets of USB power supplies for the ...

My money is on the pins. Pin money??

The next step is to make a proper set of contact pins, I will probably have to modify the cradle at some point or buy a 3D printer and learn a new skill set.