??? Scott 367 Genuine Browntoned Paper?

This cover was in a batch which I purchased (via auction) yesterday at the CHARPEX stamp show (Charlotte NC).
The cover has an American Philatelic Society "Expert Committee Report" that the cover is on genuine toned paper.

The report actually states that it is a Scott #267 while it is very obvious that the stamp is a 367 - hence a pen correction on the report (I would have demanded a corrected copy from the APS).

Is anyone familiar with "genuine, toned paper"? Could it be refering to bluish paper? If so, it should be listed as Scott 369. Obviously a previous owner though it was worth the expense to have the cover get an expert opinion. I would not think that the opinion applies to the cover since when evaluating a stamp on cover, rarely does the APS care about the cover itself. The Scott value for 367 on cover is $4.00, and the cost for opinion exceeds that, so does anyone have an idea as to what it is refering to, and possible a value for the cover?

Since the cert reflects the condition or faults found on the stamp, I believe that they were indicating the stamp paper had become toned.

Thanks for the input, Russ. The scenerio you are alluding to would be because of toning from the envelope, the stamp appears to be on bluish paper, Scott 369. A bluish stamp on cover cats for $425 in which case I would have also submitted for expert opinion. But, alas, the opinion came back - just a 367 which appears to be on bluish paper due to toning from the envelope. Very plausable explanation. Sometimes terse explanations can be interpreted in more than one way.