Good job calling them, Nick.
Interesting story.
I very much doubt he'd share the CAD files. I wouldn't ding him for that - he's running a business, after all.
By the same token, are you looking to make a profit, Nick?
Again, I'd not ding you for that, either, for the same reasons, but it makes a difference to the relationship if you are.
Are you looking for another set?
Roller rockers are much more of a known quantity these days and with the cost of CNC coming down, I'll bet there are plenty of small shops willing and able to take on this type of job at quantities we might be able to meet.
Adjusting a CAD file from an existing file by substituting measurements is a well established reverse engineering technique.
Here's a set offered by Paradise Racing for the Toyota 2TC & 3TC engine. The Toyota engine is not altogether dissimilar to the rocker gear on the Renault crossflow.
Perhaps these were also made by Rocker Arms Unlimited?
Here's a set of Titan Roller Rockers (needle rollers optional?) offered by BRD Racing for the same Toyota engine. It's an old pic but the price of US$499.00 isn't all that bad . . and that's for a single set at the retail price.
These ones look to be a little different design to the others.
https://titanspeed.com/content/rocker/I only point these out only to illustrate that there aren't limitations to one specific manufacturer.
A friend of mine used to make some extraordinary stuff for the drag bike world which was mostly for the US market. I could contact him if needed.
Cheers,
Gavin