The available clips aren't expensive, so having some made may not be expensive.
At some quantity I'm sure it's cost effective. I had considered contacting one of the usual Stovebolt restoration parts vendors and asking if they would be interested in the clips as a way to get high enough quantity to be worthwhile.
Without asking the spring manufacturer you can only guess at the price, if you're serious about it send them a sample and ask.
Another option is make them yourself.
You can buy annealed spring steel sheet from sources like McMaster Carr. Then shear it it to width, bend to shape and drill a hole. Send it out for heat treating, or heat treat yourself.
It's not hard to bend them one at a time to match the existing.
