Sadly, there's no list as such of recording dates or locations for Dandelion recordings. However, to answer your next point, many of the early Dandelion releases were put down and mixed at CBS Studios in New Bond Street, London; including my own first album ("Beau").
I was present in the studio when Bridget St John was laying down some of her tracks; also during the time of the raucous Stack Waddy!
And yes, it was the same Mike Ross as did Fleetwood Mac and many others. Mike was pretty well the house engineer for CBS at the time. He was a great guy to work with, and certainly tthe best engineer I ever came across.
Hope this clarifies one or two points. Thanks for the post...