Sundry observations:
Thanks, all, for your nice remarks about my airhead. Hans is tucked away for the winter, but when spring eventually returns, will be pleased to learn of your kind thoughts.
Brooks saddles and African climate/weather? Like you, Andre, I've seen many old leather saddles with years of maturing in the African dust & sun. But not so many on the humid lowlands beside the ocean--the high dry plateau country seems kinder, 'cos even when it rains there, everything dries out shorty afterwards. Others' experience? Maybe Dave Conroy will have some comments from his Africa trek--or maybe it won't be long enough for the Brooks B17 to mature? Or maybe he dosed it with Marmite in UK, and not even a high-veld thunderstorm could dampen the leather?
Shoulda read the early posts on this thread--I first read just the most recent posts thought it was about saddles & only today did I learn it was about Marmite. Well, I dunno about this: I think the emphasis may be misplaced, & that the Unsung Hero of the History of Foggie Olde is really bread and dripping. Took a while to extricate myself from national mythologies, but in due course I reached my own conclusions about British products of variable viscosity. I decided that there was, somewhere in that green & pleasant land, a supply of a "base" product (the analogy would be a paint base, for tinting): in its most viscous form, it's Marmite; barely thinned out it's axle grease; next level of runniness is Castrol 40; very runny indeed, and quite useful, is Dettol. Not sure what the gaseous variant might be; not sure I really want to find out...
More seriously, Dan and Jawine, your summary of the complexity of sizing saddles to bottoms is, well, fitting. Who knew?? I sure didn't. When the foam rubber in the OEM saddle on my Eclipse lost its firmness, I just bought myself a Brooks B17, fiddled and fussed for a few days 'til I got the fore-and-aft tilt right (nose barely elevated from the horizontal) and the forward adjustment right (maximum forward) and it's been wonderfully comfortable. Your exchange on fit and the factors involved is illuminating--well done! Jim Powers' similar piece from 2011 (I believe it was) in "Bike Touring News" is the only comparable piece that I've seen.
Cheers,
J.