The Honda was Alloy; HRU19D. The only Honda with a steel base at the time was the HRC commercial model. Now is probably different though. I could be wrong but they were both around the $800 mark at the time

Yeah, great point on the design team. Engineers always seem to have a way of getting it wrong. Just look at the greenfield Friction drive. Theo was told by engineers it wouldn't work, no chance. It has now been in production for over 50 years.