I tried both with and without the missus on there. Adding her only put another ~ £90 onto the quote. So not that much of a difference, really
The odd thing is, she's had her provisional licence for 21 years. She got it when she was younger so she could ride a 125 and she has a wee scooter now. But she's never had a car so never needed to take a driving test. I wonder if that's considered good? [as in has held a provisional licence for 20+ years] or bad? [as in has held a provisional licence for 20+ years but never passed a driving test]
TBH I doubt your wife's history on a provisional would count for anything, one way or another. A provisional license is just that - it is intended as a step to full legality - not a loop hope (as an aside, if you can safely ride a 125 for years, or drive a reliant 3 wheeler sensibly, why the hell wouldn't you take your test? Even a bike test, to ride a little scooter? Unless you aren't confident of passing, which reinforces the idea of compulsory CBT.... but anyway...).
Based on all you've said, Steve's comments seem sensible - i.e. mid to high hundreds, depending on what exactly you are buying. Pretty much all insurance underwriting is driven through algorithms now, based on a huge number of variables - post code is important both from the perspective of risk (of loss) but also risk of fraudulent claims (both of which impact inner cities, so its a double whammy). Few companies really do individual underwriting, though they will have a healthy "wriggle room" on their automated quotes, to facilitate the idea of negotiating.
I'd suggest you hit as many potential quote sites as you can, note the best and use this as a blunt instrument for negotiation. Worth noting that many of the "insurance companies" are nothing of the sort - they're mostly brokers - the same half a dozen companies underwrite most of this.