I did think that with 70 years of reloading, building, working on, collecting,and researching firearms I could contribute something to the forum. . .
Absolutely you can. And there is no rule against posting full serial numbers or anything like that. My comment was only because, as with most things shooting related, I figure it is better to recommend erring on the side of mitigating risk rather than on the side of taking it. As I said, I don't understand why criminal mischief is appealing to anybody, but the news suggests it is for some. I don't understand half of what politicians get up to, either, but I seem to be stuck living with it.
The rating +P+ is 15% over the +P rating. . .
I wish it were that simple, but as I mentioned, there is no SAAMI standard for +P+, so there is no standard pressure multiplier. I expect some of the makers of warm commercial loads push it higher than others. I've read in several places that there is a sort of unwritten industry agreement for .38 Special only, that +P+ not exceed 30% over the SAAMI standard MAP for the cartridge. 1.3 × 17,000 psi = 22,100 psi, and following the SAAMI practice of rounding MAPs to the nearest 500 psi, that becomes 22,000 psi, but that's not binding on anyone. For 9 mm only, the unwritten agreement seems to be 20% above SAAMI's standard MAP, or 35,000 × 1.2 = 42,000 psi, close to the NATO maximum mid-case pressure of 43,000 psi for 9 mm ball for modified M3 submachineguns, IIRC (but which is not approved for the M9 pistol).
One poster on another forum who's shot a lot of +P+ 9 mm says the label can also be meaningless, pointing out Federal 124 grain Hydrashok +P+ produces lower velocity from his guns than a Winchester 124 grain +P load does. So, it's a label a maker can put on the case, but doesn't necessarily tell you a lot, other than light guns may not like it much.
This table at Father Frog's pad sums it up pretty well: http://www.frfrogspad.com/miscellk.htm#+P
The contrast in your picture didn't show the number well, so I took the liberty of highlighting. Hope you don't mind.