I found Hamrick VueScan,
I've used VueScan for many a year now, on an ancient Acer scanner, wasn't broke so why fix it, but when the computer broke there was no way of finding the correct Acer driver, so off I went to VueScan. The only bad point being that they printed their name on the bottom of each page, but I could live with that.
When the next computer broke I free-loaded VueScan, but then found that they had printed their name as a watermark banner across every page on the latest version, and there was no way I could then download the old version and I clearly couldn't live with that ( it wasn't broke, so why did they fix it ?) so I bit the bullet and sent them money, which got rid of the watermark.
Then my computer had to be re-rigged to a previous date to get rid of a "nasty", and the date was before I had paid for VueScan, so it didn't recognose my "licence" so I was back to square one, and re-purchased it but wrote to them and pointed out that I was really paying twice over, and would like a refund of the original purchase, or if that was not acceptable then at least an upgrade me to their "Pro" contract.
That happened, has cost me a double fee - not an arm and a leg, just a few fingers - but I'm delighted with the operation of the "Pro" programme.
Well done VueScan and another satisified customer.