To answer partly to Leo's final question,
"Why aren't more manufacturer's installing ditchlights on their models"
I would imagine some of it revolves around the idea that most of the common models that would be retrofitted, wouldn't sell well to those who model era's prior to when ditchlights came into use.
For instance, I wouldn't purchase a GP35 with them installed if I was modeling the 60's or 70's.
For new equipment however, where ditchlights are standard there isn't much of an excuse.
If one wanted to make models that had the option for it, they would also have to include in the package "frame blanks" for models built prior to the implementation.
Pretty sure this will increase the costs a few bucks.
just some thoughts.
Great show Leo,
J....