ZX80 qualified repair person in Germany?

[Erm]

I have 2 non working ZX80s. I've been off and on trying to repair them for what feels like years and have made some progress, but they aren't quite there and I'd really love to find someone with the knowhow to look at them, investigate and then tell me what was wrong, so that perhaps I may learn something. They are:

1. An original ZX80. This one was in a real state, I think a previous owner had used wrong polarity PSU or something. There was a short somewhere and I ended up removing and socketing all the chips, finding 7 dud 74xx chips and a broken Z80 along the way. With replacements in place it was promising at first with a good clock, some activity on the address/data lines, but it's still not right and at best produces odd patterns on the screen, or nothing at all.

2. A clone ZX80 board (I think a Wilcox). I built it and can very nearly get recognisable video out of it (using a ZX8-CCB). The screen reacts when buttons are pressed, I can almost see letters or at least slanted blocks that are about the same length as the typed words. Other times it seems to lose the blocks and it's mainly just a white screen with the flicker when something is pressed.

Both ZX80s have LS 74xx chips but I don't have enough for both boards at the same time! Everything is socketed so that should make things easy for someone in the know. I'm in Germany, so it would be most convenient if someone over here or nearby could have a look. I don't normally give up like this, preferring to trundle on trying out suggests etc, but I've had it with these, they've taken way too much time. Obviously I'm happy to pay a fair rate.

[Moggy]

A post on the German forum may be more productive as they have quite a few ZX80 buffs over there and nearer to home obviously.

[Erm]

Don't think I'm a member there, but will do if I get no response after a few days.