Gloomhaven is awesome, but...let's replace the cardboard chits with something more interesting, right?
I found a lovely rat from dutchmogul under the Share Alike Creative Commons, and repurposed it. I mounted the rat and its base to a 33mm Gloomhaven standee base that I had remixed.
The bottom of the HP dial has a hole, so you can stack "HP extend"ers if your bot has more than 10 health...I haven't gotten far in the game yet, but maybe later? Otherwise, it's not necessary. Better safe than sorry.
I came up with a "keyfit" option, to prevent the top coming loose from the dial. Basically a small spike on the bottom dial. The top "key fit" has a slot for the peg to go through and there's empty space for it to rotate around in the top. (But the spike can only come out when the top is aligned with the "X" on the dial.) No support needed.
The HP-extend will work the same on keyfit & normal versions.