Still it would be nice to have a list of current Kamis with their respective marks and specialties.
It would be nice to have an up to date list of kamis with their marks, but not necessarily a simple, one-time task. Kamis come and go, some are part-time, some occasionally change their marks, some are used by HI but do their work elsewhere, etc. I doubt Yangdu has time to maintain such a list, but if you hang around the forum long enough you get to know most of them.
I've noticed that Yangdu usually posts photos of the right side of blades in her DOTDs. If she posted the left side, where the kami marks are, it would help people to match the kamis to their marks.
As for kami specialties, that would probably be like trying to herd cats. Sure there are specialties, as previous replies have noted, but they change as kami skills evolve and people come and go. I think the newer designs tend to be made by one kami, but as they become more established by HI, other kamis learn to make them. Some of the kamis routinely make several different models, while some make mostly one model.
I suspect that most of the kamis could make most models, but not as efficiently, hence not as economically. When you look at one of the photos inside the shop, you can see that a kami might have several blades for a given model in various stages of completion. It's the way skilled craftsmen tend to work, and it's easier if you specialize a bit, but no skilled craftsman likes to be locked down to making just one design, whether it's knives, carved birds, or anything else.
Not having a specialty doesn't in the least detract from the quality of what a kami makes. Rajkumar doesn't seem to have a specialty, unless you define artistic beauty as a specialty.