Sorted! Finally got some and by the name of the seller it looks like they are coming from China anyway. The only drawback is they seem to be coming by camel caravan on the Silk Road ETA 22nd June to 1st July and I think it is this year.
The irony of it is that I got them through guess who? Amazon Big Doh moment!
When we bought the car in 2018 it was in the RC models section on Amazon and all the spares including batteries were there and it was there we bought the spare battery. So naturally that’s where I looked this time only to find they were not available. After my frustration with AliExpress I trawled around some RC model sites hoping to strike lucky or get an equivalent type. Just happened to be on Amazon regards something else and just wondered if I put Li-Po in the search box? Guess what there was a whole section just devoted to Li-Po batteries with at least 3 sellers offering the ones I wanted doh! Now senior moment aside I do blame Amazon for poor cross-referencing of their database it is not the first time I have looked for something under one category to find it listed somewhere completely different and as for the spurious articles that pop up in totally unrelated listings!
Anyway lesson learned, try every permutation next time. Mind you the more important lesson has been go to the specialists, you might pay more but they seem a more reliable source when it comes to spares and stock. I only bought from Amazon due to my SiL it was easier to say “if you need spares go to Amazon”. I did plenty of research at the time to buy a model that Amazon were holding spares for knowing how these things can get damaged. Unfortunately, as this episode has shown Amazon are not that reliable.
Now I had better go and get my binoculars out and watch for those camels coming over the horizon