These have been on Ebay for a while now, and I like the concept since buying Rob Bayleys version. I had no idea of the quality of these sheaths and I don't even own an F1 anymore, but my slimline Deval Bushcrafter might just fit, so I took a punt.
Takes about a week to arrive as they make them to order. I suppose if you have the specs of your own knife, they can make adjustments to the retaining strap and firesteel loops etc. Anything more than that and no doubt they would need to see the knife.
Anyway, it arrived, and it is of a very high quality manufacture. Not quite up to Robs exacting standards, but certainly well put together, neat and made from thick quality leather. I didn't try it with an F1, but as it is made for that knife, you'd be hard pushed to find a better sheath unless you went high end custom.
It was good news and bad news for me. The good news, my knife slipped in like it was made for it, the bad news, the retainer strap was nowhere near long enough to close around my bushys handle. I did toy with the idea of selling it on, then decided to risk wet forming. The good news is, it worked.
If it can be made to fit this knife, it can easily be made to fit a Woodlore sized bushcrafter without too much effort. Leatherworld offer this sheath and a few other styles in different colours and configurations to suit everyones tastes, and going from this sheath, I highly recommend them.