Hi Majus,
First of all, congratulations on trying to tackle this esoteric art.
I fully agree with all of Colin's comments about the huge differences between the early Myochin work and pieces from the workshop of Takase Kozan vs. the cheap, rudimentary pieces that we often see on the market. Judging by your work so far, I don't think you're trying to monetize your craft by creating the cheap knock-offs. I especially like your carp.
As I'm sure you're aware, there are a very few other artisans working in the space, most notably Haruo Mitsuta. What I think differentiates Mitsuta's work is that he's not simply trying to copy the old Myochin or Kozan work, he is actually breaking new ground by making examples of creatures that have not been made before and using materials that add to the realism.
I understand that there is someone in Europe who is making fairly good copies of iron jizai (I haven't seen them, so I can't attest to their quality) and trying to pass them off as old examples. Although I have some contemporary pieces in my collection (including by Mitsuta), I would personally stay away from work that is trying to be passed off as an antique.
As a collector, my advice to you is if you're serious about making this a vocation, try making new subjects or creatures. Of course, there may be collectors out there who may want to buy copies of old items or may even commission you to do so, which is ok as far as I'm concerned.