The seller admits it has 26" bbls,,and that his info says Remington only offered them in 28 and 30.
It's his opinion that they are original and perhaps special order length.
It's still his gun.
The tubes not quite touching could be an indication of a cut,,but it's not a 100% rule, maybe it is here..
I don't know if the high grade Remingtons were routinely cross hatched at the muzzle or not. It's certainly not a big deal to re-create if needed.
Lacking any other photo evidence,,A carefull measurement of the lengths of the choke bore(s) and with that info a conversation w/someone familiar with Remingtons of this period most likely give up the answer to the question.