Break in

How bad is the break in period for these shoes?

I ask as I bought a pair of chukkas a few years ago in UK 7. They felt small and battered me tbh. But they've stretched now and I can wear them. Although I expect the footbed was too small anyway.

I'm potentially interested in 875s and I've found a second hand UK 8 in pretty good condition.

I usually wear a 7.5/8 UK in other shoes.

Separately, are there fakes out there and if so what are the tells?