Thanks for the replies thus far. I've done a little more homework:
1. Restoration Specialities - looked through the online catalog and could not find any
2. AMK - looked through the online catalog (page 237 and more!) and could not find any. The good news is that I found some answers to some other questions
3. Dearborn Classics - part #ICPC100 has only 4 teeth per row, not 6 like the original. Also is painted black, not phosphated.
4. Compared also to a previous post here (Feb 20) showing a 4 tooth model (like Dearborn Classics) but is in a bright zinc plated finish. Use "Dennis Carpenter" as the key words for searching to come up with one hit.
I would say at this point that, like the case is quite often, there is no great substitute for original parts.
John