@farang
An issue with older Domestic panels is efficiency which is basically the rated output proportionate to the panel size.
I bought a 240w panel a few years ago it was nearly 2m long by 1100mm wide it has long since been replaced with higher wattage smaller more efficient panels on my van.
That huge panel worked out at around 12% efficient which is dreadful by modern standards which are now in the very high teens to low 20s
So yes if you have room for them then maybe go for it but to be honest even £40 is probably too much
You can now buy brand new branded 400w far more efficient panels for <£60 from places like CEF.