I think the Tranmere one (Semplex?) is no longer there.
Flailing hedges is certainly bad News
if you are looking for sloes. You need unkempt hedges. They are the fruit of the blackthorn tree, so be prepared for thorns.
There was a brilliant crop of wild plums too, this year. There were so many that the weight had broken the branches in some trees. We tried them as a substitute for sloes, and I will report back on how they turn out. We have six litres of it on the go, and so far it seems to be doing fine. It has turned a deep dark red anyway, and the plums are shrivelling as their juices are leached out. You are supposed to prick them to help this, but I doubt if it's really necessary. I think osmosis is the main thing that is going on. The colour comes from the skins, of course, and I assume the juices 'osmosing' through it is how the colour is brought out.
Some people stick them in the freezer and freeze them solid which is supposed to break up the cells to release the juice, but again I am sceptical.