US Scott 753 On Cover Front

The special printing 753 was perf 11, it was not imperforate, according to my Scott Specialized.

When reading the Scott Notes after #751 regarding the special printing it specifically stated that the guidelines only appeared on the #753 (which is not gummed). Would someone perhaps have a copy of a full sheet of #733 & #753 (uncut 200) to compare. Scott only notes Center Blocks, Horizontal or Vertical pairs, Arrow blocks in the #753 description. There is no mention of these items in the #733 description. I can recognize that if a single (or unlined block ) on cover can only be thought to be a #733 but the cover illustrated shows guidelines and a partial arrow which if true to the Scott Identification would be a #753. Would Scott or Mystic (or other site) have a comparison picture available to post if no sheets available for scan by member?? I have searched sever on line stores with no results. (maybe Postal Museum???

My understanding is for single #753, evidence of a guideline is sufficient, although a pair straddling the line is more desirable. For those that say guidelines are present in both 733 and 753 sheets: if that was the case, there would be no way to even distinguish the pairs.

I think the confusion arises from the requirements for identifying the stamps from the imperforate sheets, i.e., distinguishing #735 from #768. In this case, the only way to determine #768 is with pairs that straddle a gutter. A single #768 will not have sufficient information to determine the stamp is actually a #768, hence it will always be classified a #735.