Hi Ste,
Nah, believe me, there were plenty of people that attanded the Wheel, well Whitworth Street at least, that also attended the Casino, I was certainly one of them at 22 years of age, and nobody called me "grandad"
And as you postulate, a lot of us drifted there as a natural progression and as other clubs we attended faded away, eg Blackpool Mecca, Golden Torch, Up The Junction, Catacombes, Leeds, etc.
Also, what filled the dancefloor then, didn't always translate to what was being collected, well not by me anyhow. On the contrary, it was during the early Casino days that I picked up a lot of what got played at the Wheel on UK labels missing from my collection, and all at rock bottom prices. In fact, I used to have people bring me records I was after from the earliest days of the Wheel on Whitworth Street, for pence not pounds. Aaaah, them were the days.
But to answer your final quote on the subject; yes, I would also guess that for many others of my age and older, the Casino probably spelt the end, at least for a while. But sadly, for others, perhaps forever.
Denbo.