It is very unlikely that Old IHC made their own light buckets and retainer rings. try this link.
https://www.google.ca/search?hl=en&sxsr ... 45&bih=881 It was posted, on this forum, many years ago, IH used the same headlight bucket system as a popular school bus builder. possibly Blue Bird.
The retaining rings for my 1940 Ford are the same as the early 1950s IHC. I have a drawer half full of IH buckets and retainer rings. NO, I am not going to ship these to you. If you were close to Vancouver, BC, I would give you a set. Get out there and do your research. I had to do this on my own 50 years ago when I got into this IH truck thing; Check your local IHC truck wrecking yards for the parts you need. There is lots of cross-over in IHC parts.