Ok - I'm wavering enough to tell

if I was a bit more convinced, I'd probably not want to !
It's a declared new on import' 1991 'blue & white' bike with a kph clock. It reads around the 32,000 km's. A Three Legged Cross prepared bike. I think 3 (maybe 4) P.O's, the latest has had it for only a few years, he's now in his 70's & knee problems have stopped him riding. The last but one was according to the 70 year old, "getting on" too !
He openly admits that when he bought the bike, it was immaculate - now, it's still pretty good, a bit of the coat coming off the wheels, some road crud which has sat on the fairing panels & the odd chip/scrape, but no sign that it's been down the road. It's been off the road since last summer, because of the chap's health. It was started & running the other day, but he admitted he'd had to get the plugs out to 'clean them' to get her running, hence the fairing was all off. There's some oil misting around one head, but nothing major.
Exhaust Can's look too good to be original ? - they have an impressed logo....like the "Puma" sports kit puma ? a big cat at full tilt ?? not sure what make that makes them ? pipes look to be fine - not sure, if they are stainless as standard ??
The starter motor magnets have been 'fixed' ? a common problem ?? they were glued & not riveted ?? anyway, they've been done, & the service schedules been kept something like, re oil & filter changes. There's quite a wad of service dockets etc, but latterly it's not been doing many miles. It was on about 19k km's in the mid 1990's.
It starts, runs, sounds fine, some bit's of tidying need doing, under edge of fuel tank feels a bit 'rough' probably needs attention.
He's looking for a 3 figure sum starting with a 5.....
I can't believe I'm hesitating!......I have a contact who could actually do Colonial Boys sprocket adaptation, if that is a straight "fix" ......but I have no idea what's "right" price wise in the Uk, you don't see many about !!