I know. This is why people try alternatives ways. Plus, it makes things more interesting and inspires more creativity.
If just looking for a true replacement, I’m not sure anything but the original is going to satisfy. Then it gets down to how original the product is within the same manufacturer. Then we’re at gearslutz level. Slippery slope.
The main problem is that at the moment you have to change the HF feedback, you have no idea of what you are doing! Most people don't have an advanced measurement setup, so you have to do the change 'by ear'.
With the result that you can create a completely different microphone!
I have measured many K67/K87 capsules in the past and the conclusion is that they are all different.
To my surprise the RK87 by MicParts was almost identical to the original K87 from Neumann.
(But maybe I was just lucky...)
That is why I asked about the HF response. Ideally, it should be a drop in replacement, without any changes to the circuit.