Hi and welcome!
I am very sorry for your loss! The best way to find a character compatible friend for George would be dating at a good standard rescue under expert supervision, so you can be sure that they get on and you do not run the risk of ending up with two single boars. All our recommended rescues practice a mandatory quarantine and vet clearance in case of medical treatment, so you are guaranteed to rehome a healthy guinea pig that can live with his new boarmate straight away.
if you find that George is acutely pining, i.e. not eating and giving up on life, then you need to find him a friend asap. In all other cases, he should come out of deep mourning in a few days, but be very subdued.
https://www.theguineapigforum.co.uk/threads/looking-after-a-bereaved-guinea-pig.110463/
Unfortunately, there is no good rescue close by, but the RSPCA Bryn Y Maen centre near Colwyn Bay currently have got a single 3 year old boar that is desperate to find a new friend himself; it should be within your reach. they offer dating at the centre.
Your other recommended rescues are the Potteries or the RSPCA Walsall (which will only boar date rescue born babies with single boars, so available).
https://www.theguineapigforum.co.uk/pages/guinea-pig-rescue-locator/ (we can unfortunately only guarantee for these rescues that they are operating to a good standard of care at all stages and are piggy savvy; in all other rescues you do so at your own risk, especially in view that anybody can call themselves a rescue). If you prefer to source a piggy from anywhere else that does not practise a mandatory quarantine, you will have to conduct on yourself, which of course prolongs intros.
Here are our forum tips:
https://www.theguineapigforum.co.uk/threads/importance-of-quarantine.108034/
https://www.theguineapigforum.co.uk/threads/single-boar-seeks-friend.129032/
PS: Boars of all ages can be bonded, provided they like each other and get on. We can provide bonding tips if necessary.