Thank you all guys!
Regarding the trees... Those are K&M trees mounted on Snapdragon Studios tree stumps. The later were quite large resin pieces, where I drilled into the top, so,they would take the wire for the K&M trees. Unfortunately Snapdragon ceased trading for health reasons about half a decade ago and they have not sold their moulds to anyone, so I think it will be near impossible to get more these days.
Not a cheap solution. I have about 60 trees (leaf and firs) and I think they cost me about 500 GB£ in total. On the other hand they usually draw lots of attention at shows, so I think it was a good investment!