If you have a look on this forum at both self treatment of steering wheels and getting a pro out to do a refurb, you will be gob smacked at the quality of the finish. Some amazing work. I don't have the post to hand to link, but the guy who did it bought the dye kit off eBay from a specialist in leather dyes, did an amazing job and was something in the £20 range price wise.
For alloys, a standard powder coat will be more robust than a diamond cut. I can't tell on my phone if those alloys are originally diamond cut, but if they are, they are silver on silver and so a fully standard powder coat would look virtually identical. Alex225 had his S class alloys recent diamond cut, and went for a light grey on the inside of the run to accentuate the diamond cut, rather than leaving it all silver. Worth looking at his thread and amaze at the quality of his car cleaning. He also has some good photos of before and after leather treatment by a mobile pro.
If you can arrange it, Lepsons in Gillingham for alloy refurb is one of the best in the country. I wish I'd been able to get mine done there, but Coronavirus scuppered my chances of tying it in with a trip to family close by, so I went with Speedwells east Birmingham.