so, it turns out that the valuer didn't really know what they were at - and didn't realise that saying we needed to repaint (under the 'essential repairs' heading in the valuation report) would mean the bank would retain part of our mortgage. and these people are supposedly professionals !?
in the end we've had to run around for 2 weeks getting quotes for different things and the bank are retaining a few grand (thankfully not too much), but it has meant a delay of about 5 weeks (it took them 2 weeks to tell us about the thing in the first place and another week to get back to us after we'd submitted all the quotes), and in that time interest rates have gone up again!!! grrr....