The conversion kits available in the 1980s were to convert the
carbon-arc to a Xenon source, not
HMI. Most localities' Clean Air Acts would prohibit the use of a device that emits massive amounts of carbon monoxide indoors. Even if the fixtures come with a 30-year supply of carbons, no one will want them.
The fixture was discontinued by Strong in 1982 for many valid reasons. Though many LDs lament their loss, today they would be considered unsafe and possibly illegal. Plus the fact that expert operators are becoming extinct daily.