Discovered this today
 

This is from Kolar’s website.

In the late 1980s, a significant development occurred when Remington Arms approached Kolar to manufacture 10 prototype Parker side by sides. This evolved into the 90-T project, a single barrel trap gun dedicated to competition trap shooting. This collaboration proved to be a turning point for Kolar Arms, significantly influencing its trajectory in the world of trap shooting. The 90-T gained popularity, establishing Kolar’s reputation in the competitive shooting world.

I always thought Remington did this in house.

As I understand it there was still Kolar made parts like frames still in the Remington Archives.

The 90T was a joint venture by Remington and U.S. Competition Arms. USCA became Kolar. The barrels were made in Ilion and shipped to USCA to be fitted to the receivers, which were made in Racine, WI. Completed guns were sent to Ilion for testing and placing in the warehouse.

When the PGCA Research Committee went to Ilion in 1998? to copy the Parker records, we found and examined the Kolar made parts in the Archives. They were all stored in wooden boxes. We took pictures of them in case they were never used to make guns. Unfortunately, they were not used to make any quantity of guns and are still there, as Brian suggests, or sold off to souvenier seekers. I was not aware of the connection between Remington-Parker and the Kolar built Remington 90-T.

Wow, Brian, the young Bill Murphy (eightbore), holding the receivers of the planned five gun set of Kolar-Parkers. Unfortunately, the plan never came to fruition. The gun Bill is holding is the unique Parker Trojan skeet gun.

Since you mentioned the Trojan Skeet...
 

Some pics.

And the letter
 

Letter