I know of the cheap models like Cimarron and Zhangzhou, and I know of the CZ hammer coach and hammer classic. I also found the Pedersoli La Bohemienne. Are there any other manufacturers (other than H&H etc) making these guns in 2017?

I think "Bernardelli" not sure about Spelling, but I think it is right. it is a beautiful shotgun, he uses it for trap and skeet. It is pricey. But it is a great shooter.

Baikal is probably still making them, but as far as I know they're tied up in the Russian import ban.
You can still find them used.


ETA:
On the other end of the price spectrum is the Beretta Diana.

There is apparently still a market for hammer guns in Italy.  A number of the name brands over there make them, tho they rarely send them to the US.  Very nice stuff.  Friend picked up a Vicenzo Bernadelli 16 gauge hammer gun recently.  Beautiful shotgun and he is deadly with it.

Unfortunately Bernardelli is out of business, according to their website.

Avoid the Cimarron Arms CoachGun offering. It is a complete piece of junk! They used to get good reviews from the CASS crowd but Cimarron now gets them manufactured from a different Chinese factory and they are just poorly made. Mine when back to Cimarron one day after I took it out of the box because you had to dissasemble the gun to remove spent shells. I received it back with only marginal improvement. It would open after shooting very light loads but nothing else. Then a hammer spring broke and I had to have that replaced by a SASS smith I found at a local shoot. I have polished the chambers and it still is very sticky to open. Poor fit and finish as well including factory buggered screw heads and some sort of painted finish on the barrels.

There are a number of bespoke english makers that turn out proper hammer guns...Boss will make you one if you have the $$$.  They are lovely shotguns, well made in all respects...but you pay for it.