Opinions vary on Dalesford drive units, as you ( Spendorman ) and I know.
I use to think they were one of the best, as they made a driver for Rogers.
Presumably it was labelled 'Rogers' rather than 'Dalesford.'
I though RAM only made the LS3/5a when I discovered them!
That was back I the '80s, if I recall correctly.
MARTYN