As the work is being done in Germany could you not get the TUV approval at the same time, on a sort of belt and braces approach?

With the main problem I think being travelling through France have you considered cutting it out and taking a ferry to Zeebrugge then on to Germany. It might simplify things or it may not, rules are changing daily. Good luck.

That's a possibility, Julie, but knowing the rues for France were going to change at 4am this morning, that would still be my favoured route. Entering France is relatively straightforward, as long as you are double jabbed, returning home is just a tad more complicated with a PCR test required within 3 days of your return. That shouldn't be too difficult to arrange and I have a pal who lives over there going to set that up for me. Many pharmacies offer the tests at a relatively reasonable rate. No quarantine when I return and just a Day 2 PCR test by post. One has to fill in a Passenger Locator form for the UK of course. As far as my research on Germany is concerned, I think I just have to fill in an on line form, again, as I am double jabbed.

I still need to double check all this but I think it will be ok. Not as simple as things use to be but, hey..