welcome and a very nice example, should be worth £22+k but it isnt.
New £35k and they are now £12k ish. it best guess as £50k with all bits new so£16k - £18.5k
if he took to dealer i guess £10 -12k cash £11 - 13 px and £19.5K on forcourt (the owner has now hung himself)
this will sound very corny but its really only worth the most you,d pay and the least he would let it go for.
IMHO your better to get guide value from a dealer as forums can be wildly wrong.
Tony