Substitute for the PNP D45H11 transistor?
I guess I'll write an answer. (Actually, you have some good clues already.)

One place to go is to Digikey. They have a reasonably complete search engine for questions like this. I plugged in transistor in the search bar and got a nice dialog thing where I could plug in \$I_C\$ and select some gain values and plug in a minimum \$V_{CEO}\$ value, as well. Plus the TO-220 packaging (there are nearby packages, but why not make it exact?) I also added the in-stock choice. (If Digikey isn't carrying it, then perhaps you shouldn't consider attempting to use it, either.)

Of course, the D45H11 popped right up and from several sources, too. (As it should.) It's cheap and they have them in stock for about $1 each. I don't know why you can't get them. I'd just order them, in your shoes. But there is another option that popped up (other than a near look-alike from OnSemi called MJF45H11G.) It's the Fairchild BDX34C, which is still cheaper yet. So if you really can't consider the D45H11 for some reason, then take a look at the datasheet for the BDX34B or BDX34C (here) and see if you think it might be okay to substitute. It's 76 cents, too. (I'm not going to walk down the parameter list for you -- you can ask if you have a question, later.)