Not all sports stuff, but I restore the occasional thing. I don't usually call what I do restoration, as most can be reversed with ordinary hand tools.
I collect bikes, usually ones ridden by pros or at a pretty high level. Some I have to make parts for, since they were team only and just aren't around to be bought.
1920's? Bike built for motorpacing - basically having a motorcycle run on the track ahead of you to draft behind.
Built for the US team pursuit team at the 1983 Pan-Am games. I had to make the front hub and handlebars. The wheels are 24 inch, like on a biggish kids bike, and not easy to find.
And a couple random things. That are "restored" A lawn chair that was probably 1950's, and a bench. Both scrounged from the curb. The bench was pretty much just the ends when I got it, all the wood was mostly rotted away. The chair was pretty rusty, completely derusted/repainted, and reassembled with stainless hardware. (Ok, not a textbook restoration, but better that what the trash truck would have done to it)