If you haven't read this interview with Tom Roberts of Black Dog Books, you should take a look. It will give you a good idea of what Roberts is up to. Since I'm a sucker for a good pulp yarn, I thought I'd read one by Harold Lamb, having recently read this article about some other reprints of his work.
The Skull of Shirzad Mir isn't a novel, exactly. It's five connected stories about a Moslem warrior named Abdul Dost and an English merchant (who's quite a warrior himself), Sir Ralph Weyand. The first four stories are narrated by Abdul Dost. The final one, by far the longest, is told in third person. Dost and Weyand are unlikely allies, and Dost doesn't quite trust the Englishman, who's impetuous and daring, but Weyand keeps coming up with clever plans that Dost admires after they're successfully carried out.
The stories are colorful, full of action, well-written, and (as far as I know) fairly historically accurate. They're all set in India in the very early 17th century, and Lamb provides notes to two of the stories that indicate he either did a lot of research or was a good faker. I think the former is the case. If you're looking for old-style adventure with hair's-breadth escapes, intrigue, swordplay, horsemanship, and even a bit romance (in the latter two stories), you can't go wrong here.