Hi,
Excellent attempt at keying out, but worth noting that Kibby’s “synoptic key codes to British boletes” excludes Suillus, Leccinum, and Xerocomoid species.
I suspect this to be one of the Xerocomoid species, and if keyed out using Kibby’s “Key to Xerocomoid boletes”, might get you to something like Xercomellus subtomentosus.
Regards,
Mike.