I don’t have any definitive proof on this, but AFAIK, TRK only marketed lcrowns, they didn’t make them. This is supported by the fact that they’re not leaded, and it makes no sense that they’d have a different process for unleaded chips, it would have required a pretty big change to their manufacturing process.
USPCC did made some of the initial ones, as I recall. I do have a Burt & Co order form somewhere for some Lcrowns, so I do know they made them.
I've been trying to figure out the chronology of Large Crown chip manufacture, and this it what I've been able to dig up so far.
I think that
TRK began making their own Large Crown chips sometime between 1940 and 1947. In their catalog roughly dated to the 1940s, they introduce a new line of "Mercury Speed" Large Crown chips that all have new different colors and are 50% heavier than their older Large Crown chips. Presumably they are 50% heavier because a lot of lead (or some other metal) is being added to them. (see image below)
The first new extra heavy Lcrown colors are Grey, Orange, Green, Crimson, and Blue. In the same catalog they offer their older "standard weight" "King's Registered Crown Chips", offered in Red, Blue, Orange, Chocolate, Light Green, Lavender, Light Blue, Pink and Black.
I suppose that it is possible that the Burt Co. was making the new chips in new colors, but I had assumed that
TRK was making the chips themselves. Burt purchased the
USPC Co. equipment (and likely their clay chip/dye formulas) around 1947. Presumably
TRK would have had to create new chip/dye formulas, which would explain why they have different colors.
If you have a Burt order form for Large Crown chips, I would love to see it, as that would completely change my thinking about these chips.