1869 No Grill Pictorial Question

It was my understanding that you could not get an 1869 pictorial no grill specimen certified unless it had OG. Given that statement how does one explain PF certificate 314847? When I saw that, I went through the other no grill numbers in the PF data search. It appears that there was at least one 24 cent and twon 30 cent unused no gum specimens certified as genuine. And these were not old submissions either. Personally, I never understood why gum was vital since the design, paper type and presence or absence of a grill should be able to be determined by examination of the paper, not the gum. What would the worksheet ofbthe above referenced stamps typically say?

It probably has traces of OG over the grill.

The sole certified Used 3c 1869 without grill came off of a cover with its' gum largely intact.

If YOU GO TO Frajolas board for philatelists, on the message board
Scott Trepel will have all the answers you have in question about 1869
without grill
GM SADUSKY