you can Script mine them solo here
https://prohashing.com/ and get paid for mining solo just read how to
or pool mine and share any blocks you find.
I think only one exchanges trades them now here
https://www.cryptopia.co.nz/Exchange so it can be very risky mining them unless you trade them right away and it's still if e.
I think there is one other set of pools that has a 42 pool still set up. master something pools in Germany.
some one some place buys them with a high value, not like they used to be but not bad .I used to mine them when btc were low in value and it was 4 btc for one 42 then 42 were hard to mine , now there not.
0.12250001 btc per 42 now