Hello, lovely to see you here again
How lovely that you're helping this little guy, I'm so glad you and your mother cared enough to offer help to these two gentlemen!
I can't offer any advice really with the grooming but I can offer a suggestion for his skin. Coconut oil is very soothing and nourishing for doggy skin, I apply it to Pebbles' skin whenever she is slightly itchy or sore. Plus it's ok for dogs to eat so you don't have to worry about him ingesting it. I would be worried about applying sudocrem to areas where he might be able to lick it off. The coconut oil should be raw and organic to provide the most benefit, it's available in health food shops. Good luck!
Your 3 are such cuties