IMHO, your solution looks too weak.
https://www.xs650.com/threads/heavy-metal-rust-removal-and-plating.56382/page-6
I did a lot of experimenting, and in the end I got half-decent results. Here's my most salient observation, copied from a post I made in Jim's thread above:
Here are my Deep Thoughts regarding DIY plating. If you go back to post #2 in this thread, and watch the video, that guy is plating in a vinegar solution. Vinegar is acetic acid, and like all acids (with the possible exception of phosphoric acid), it etches steel. Think about it, your part is in a vinegar solution which is removing material, while you are simultaneously trying to deposit nickel on that material. Logic tells me that something has to give.
I got poor results when I followed the video instructions to a tee. He uses a weak nickel solution and a low electric current. I concluded that you need to really hit the part hard, getting a layer of plate on it as quickly as possible, before the ascetic acid can remove much material.
So, that's what I did. I made a very dark green nickel solution, and I used a more powerful power supply. I also went to a much smaller container, to "concentrate" the voltage, so to speak. And, I started getting much better results.
If your voltage is too high, the plating will flake. I tried beginning the plating with a high voltage to quickly "cover" the bare metal and prevent etching, and then I'd switch to a lower power supply to build up the nickel thickness. This seemed to work pretty well.
My results are okay, but I wish they were perfect. Others seem to be getting better results, either that or they're lying, and I'd like to know what they're doing that I'm not.
I spent a lot of time researching commercial plating, trying to find out if they are plating in acid solutions. I never found my answer, but I suspect not. I also looked at the Caswell nickel plating kit instructions. They use distilled water, but I don't really know what the chemistry of their process is.
I'd like to be plating in a non-acid solution, if that's possible.
(END)
In my final experiments, I was getting complete coverage in about a half hour. I'd keep on plating for another 90 minutes in order to increase the thickness of the nickel. If you plate too much, things can get squirrely, and the plating can begin to peel.