It is truly amazing how much time it can take to complete a seemingly simple task! I had to fabricate a custom heat muff to supply preheated air to the carb heat side of the airbox. I built it first via trial and error in cheap aluminum, then used the pattern to build out the final form in stainless steel sheet with ss rivets as well. So far so good, I'll have to test it to make sure the air flow and heat is sufficient.
I'm glad I have a carb temp probe so I'll be able to truly verify it's effectiveness, otherwise I'd be a bit nervous :-)