Your H sounds, basically, like a "grumpy old man". Kind of cute, in a pain-in-the-a$$ kind of way. Sometimes I wonder if grumpy guys are using grumpy to keep people at arms length so that they don't have to engage in give and take and intimacy.
Have you ever thrown him a surprise party? Don't laugh. I really wonder how he would feel about it. When's his Birthday?
As much as he probably hates anyone making a fuss for him (God forbid anyone give him a reason to be gracious and happy), it just might give him a smack upside the head.
Does he like ANY activity? Do you do anything together? Would he be open to it? (I feel silly just asking that question, because I think the answer would be a big fat "no".)
What makes him laugh? If you can't get him to be proactive and do the work... Well, laughter is pretty strong medicine.
My H and I are chatting and laughing much more lately, and it really makes a difference in how happy a day can be.