Thanks for the mention, but I have to agree with those who say that it generally doesn't make economic sense to re-cover a Professional saddle. Even if there's someone in your LBS who's willing, and capable, to effect such a service it'll probably cost more than buying a new saddle - and it'd make even less sense if you were to think of trans-Atlantic shipping, to add to the cost.

As many will know already, Brooks are now offering a re-covery service for any model of their saddles that is still in current production. Apparently the cost of this, including return shipping to US, is $98.00 (check this, in case it has increased consequent to substantial postal rate rises in past couple weeks), but you would also need to consider the additional cost of getting your saddle to them in the first instance. They would fit a new factory-made leather top, which would almost certainly be cheaper than a 'one off' hand-made option - although some might consider that it was also of inferior quality, of course.

Don't think that I'm recommending the purchase of a new replacement, though, as there are many good used examples to be found on eBay, CL and others if you're patient (usual caveats apply, of course). I'd suggest that you'd do best to look for an earlier model, as quality of these saddles generally declined significantly in the late '70s/early '80s - and (at least if you were buying on eBay UK) you're also far less likely to be buying stolen goods, if that matters to you.

More broadly, I'd suggest that it's seldom worthwhile to have any post-war saddle re-covered excepting a few obvious rarities. The 'big ticket' saddles at the moment seem to be the alloy girder-railed things (mostly, but not exclusively, Ideales), and, if you simply must have a 'pristine' FT 57/59/65 or suchlike (and can find suitable 'correct' frame /fittings), a hand-made re-covery is a good option - but NOT for the ubiquitous TB90s, I'd suggest.