I'm a big fan of Brooks saddles, but what is putting me off (and I assume everyone else) is the lack of history.
It looks like a Team Pro with copper rails (currently £80 from
Wiggle)
http://www.wiggle.co.uk/p/cycle/7/Brooks_Saddles_Team_Pro_Saddle/5360023045 but why has the nameplate been removed? How much use has it actually had? You say 'reasonable condition' but on this one the logo stamped on the side has been worn almost to invisibility; and instead of being smooth and shiny like a normal used Brooks it is completely matt, which suggests that it has been blathered in so much Proofide that it will stretch and sag as soon as it is ridden.
You can get a brand new B17 for not a lot less than your friend is asking, so I think your friend is being a tad unrealistic on price. I might be interested if he can say 'yes, I bought it in xxx and I've done xxx miles on it and it's this colour because...', but at the moment it looks like something he got off an
Ebay bike and has tried to restore.