If it's as good as it looks Alan, it should be a very nice car. As 142Guy indicated, you'll need to tell your friend to use 98 octane aka BP Ultimate, Shell Super V-Power etc. Sadly we don't get 100 octane any more but that if memory serves was 5 star fuel.
A Lead Replacement Additive added to the fuel on fill up (ideally just before filling so the petrol mixes with it as it goes in) will help to combat VSR but eventually your friend may want to have hardened valve seats fitted.
I'm guessing you're going to get a temporary insurance cover to drive it back for her? Also that she's insuring it on a classic policy?
Many classic policies actively prohibit other people with "Driving a vehicle not owned by them" type insurance policies from driving the insured car - both of mine have that codecile in the policy wording.
Do your own checking to ensure that you are in fact covered to drive the car, after all it's your licence on the line (usually a minimum of 8 points for no insurance) and her car that could be siezed if there are any anomalies you've overlooked.
Other than that, it should be a nice day out for the pair of you and another nice Volvo to the mix!
