Found in Avonbridge by Joe Pason.
‘RESCO’ or ‘RESGO’?
Find location would suggest Scottish origins but …
The stamp has the look of a Craigend Refractory, Falkirk stamp and it is of note it was found alongside a ‘Craigend Falcon’ fire brick.
It is of note that there is a Company operating out of Pittsburg, USA called Resco Products Inc and they manufacture many refractory products including fire bricks.
(Note – SBH – I have emailed the company and sent them a photo of this brick to try and ascertain if it is or is not one of their products from the past but unfortunately, they declined to reply).