Looks like a nice mid-point between a Dickson Style, and a Swiss Multi-Fix tool post.
Got a milling machine? Make a batch.
No need to Harden them, as they have to withstand your own use, rather than the abuse of the wage monkeys that don't really care.
If you are not willing to make a batch, look hard at the Chinese 40 position tool posts, a clone of the MultiFix, which, by reports that I have read, doesn't entirely suck. CreateTool, on ebay IIRC. Other than that, you are stuck looking at all the rest.
I feel yer pain, as I have a hand full of tool holders for a tool post that I have yet to find at a price I am willing to pay, and I also have a very nice Italian made tool post that has a set of tool holders, but to my taste would be much better with about twice as many...
Looking at that one, most of the cuts could be done with just a basic milling cutter in a vise. Depending on how adventurous you were feeling, the radius that the tool seats against the post could be done with the mill, or lathe, or roughed with the mill then finished by the use of abrasive paper wrapped around a spud of the correct diameter. Or rework the design to have two flat planes in place of the radius on each side.
One place that 'might' be worth a try is on the practicalmachinist site. Post a want ad on the Tools and Accessories sub-forum. Someone there might be able to put you on to a name, if the company still exists or not, so at least you know what to ask for.
Good luck!