Most dealerships don't have enough loaners for their warranty customers, so if you're driving something out of warranty, better have a backup plan. Only time I ever see a classic, and now, even an S1 Disco, it's at the back of the lot. Dealership's service departments are, regretably, tied up working for LRNA, and not the poor slob driving something out of date, style, and warranty(unless, they have a new RR at home in the garage, and even then, probably come in with a case of beer to schmooze the guys to get them to move their baby up the list.
While it isn't true at all shops, most dealership techs who can't solve the problem with Rovacom or AutoLogic, simply can't solve the problem, period. Being ACE qualified, doesn't imply they came out of school with the experience to diagnose without $10 grand worth of testbook. As a guy progesses and gets better at the older stuff, he becomes more valuable to the independant shops, and dealerships won't match the pay because there are 20 more guys looking for a job, who don't need to be as good because the dealership is going to get paid, whatever the quality of their wrok, by LRNA.
I know you took your Classic to an Indy, and hopefully he turns out to be good. If he is, then waiting may be all you can do, his livelyhood and backlog is what it is because he is good. Under ideal circumstances, the guy will call you with his diagnosis, and time estimate, but life ain't perfect, and sometime it takes as long to find the problem as it does to rectify it. The good thing about Rover's poor quality issues is that most qualified mechanics have seen the problem so many times, they can diagnose it in their sleep. It's only the truely weird stuff that drives even the best of them buggy. Some good dealer techs moonlight also.