Hi Jim!
Please, could you favor us with side, top, and oblique front-quarter views of your saddle? You've got me really curious as to how it looks.
Has your Brooks ever gotten wet?
On the face of it, I don't think your Proofide applications have been excessive. Having/had a half-dozen Brooks saddles, I have come to the conclusion I prefer them hard, and so limit my Proofide applications accordingly, as the treatment does encourage some stretch if applied to excess. I usually apply one one thin skim coat to the underside and that's pretty well it for the duration of ownership. The top gets a very thin coat, is allowed to sit 24 hours in either sunshine or a warm room, then polished off. I do similar reapplications about once every 18-24 months. I also always allow the saddle to dry thoroughly from my body moisture (sweat) and always, always, always cover it if there is even the slightest sprinkle of rain and I'm not atop it.
Most people don't care, don't do anything special, and do just fine, so take this as a data point.
Yes, the tensioning operations are hard. The bolt does turn to a degree, just as you've found, so the net amount of tensioning is hard to determine.
One caution I will add is to be aware that (eventually) tensioning brings diminishing returns. In time (the ripe fullness of time, as in years), tensioning will result in a ridge longitudinally through the center of the saddle. This has led Jobst Brandt to dub Brooks and similar leather saddles as um, "posterior hatchets", since one is riding on that ridge. At worst, it can feel like you're being cleaved asunder. Still, I see the occasional saddle with a really extreme case of center-ridge and the rider continues on happily.
And, too, these saddles are handmade of natural materials. I have found otherwise identical saddles can vary greatly over time in terms of how they shape to the rider and how much they stretch (the two are related), and how thick the leather happens to be. I used eBay to sell one that gave out early. I had warning -- the thing was past fully broken-in by the 200-mile mark, despite very sparing applications of Proofide. Unfortunately, this was the saddle I was using to tour Europe, and I persisted with it to the end, resulting in a visit to the proctologist to determine if the bleeding I had was due to the saddle or health-related factors. It was the saddle that caused my abrasions. I received a nice note from the eBay buyer praising me for selling him the most comfortable saddle he'd ever owned, so it just goes to show saddles vary as much as individuals.
On the other hand, I have a lovely honey-colored, chrome-railed (meaning they *will* break eventually) B.17 Champion Special with exceptionally thick leather and chamfered sides that may not fully shape to me in my remaining lifetime. It is fortunate I prefer my Brooks saddles remain pretty firm.
If a saddle becomes truly misshapen and problematic, the cover can be fully detensioned and reshaped in water, plumping up the low spots and removing the center ridge. My neighbor had great luck doing so, and simply let the leather air-dry afterwards. I've drilled out the rivets and re-riveted a number of saddles; the cover is removed and replaced pretty easily. but one does have to follow a sequence of steps or get caught out with a cover too-taut to replace. These are not exactly Brooks-approved operations, but at a certain point, it really doesn't matter if the saddle is otherwise unusable. I re-riveted mine 'cos I like the appearance of the hand-hammered copper rivets better on some than the original plated steel versions.
The bike surely looks nice, Jim.
Best,
Dan.