pretty obvious this was a gun built in the UK and was just imported by EPI. They did a good job of being minimal with their import mark but its not like this gun has any historical significance.
getting with remington i think will be futile. that action could have been bare or rebarreled. Remington has been sold re-orged so many times, i doubt you'd get any information on a gun built in 2019, but what for? Its not in its original configuration and it doesnt actually matter what it was before.
all that matters is if the gun was built well and it shoots good. I do think its kinda neat its got the british proofs, its not something you see often. but it explains why its been threaded, the Brits have been using moderators more widely than we have for longer. i would double check that barrel thread, highly likely its metric.