have you tried contacting panther martin?
i will say this, tying on a treble would be trickier than a single hook for sure. aside from that - the pattern would be relatively easy to learn to tie. its just some red yarn for the "tail", yellow chenille for the body, heavy black thread or possibly black wire for the spiral rib, and some soft hackle up at the eyelet held in place by a simple thread collar.
you could easily replace your treble with a single hook and ive heard of folks doing this with great results and still fantastic hookups. its a way to C&R for trout, especailly with a barbless hook, while using spinners.
its basically a varient of this fly with a red yarn tail like a wooly worm has, and no wing.
https://youtu.be/cyaRgHGz82oit would be a simple to produce fly in a single hook format, and i'm sure any custom tier would be happy to knock them out by the dozen for you, very cheaply if you didnt want to take on the task of learning to make them yourself.
HTH
[edit] i will say this - dressing that hoook with it still attached to the spinner will be an absolute pain in the @$$. thats done prior to assembly of the spinner. so you'll be cutting the trebe off no matter if you wanna learn to dress that hook as a treble or a single. just something to consider.