Onkel Otto, who served in the Luftwaffe during the 2WK, left me his fabulous old Lederhosen when he demised. Sadly, although in excellent overall condition and generally nice shape, they have become a bit stiff with age. They have that perfect and much-desired air of having been worn everywhere (in the Alm, on the battlefield, at Trachtenfest and Oktoberfest treffen), and were a favorite part of his Bayern wardrobe.
What I wish to know is this: what sort of restorative efforts can I SAFELY make upon them so as to make them less stiff and more supple? I've heard many stories about what NOT to do to Lederhosen, in terms of applying restorative cleaners, cremes and solutions, but is there actually some sort of restorative preparation I can apply to the leather that will help soften them up without harming it?
Since I can't wear them continuously (and thereby help bring them back to life naturally, through regular wear), I need to know what I can do to remove the stiffness and make them more wearable. I've attached a picture of them; they're quite angenehm, really, if in need of some softening.
Any help would be appreciated (and yes, perhaps one of these days I shall even visit Herr Lipah at his wonderful Lederhosenwahnsinn
shop to ask his help!