Sometimes a grill can have some "skipped" points which can be caused by a paperfold. In my opinion, the grill you show is fake. The points do not line up, but roam around pretty badly, something not possible with a genuine grill.
There was/is a dealer in Ohio who was/is selling lots of fake grills. He bought a lot of his raw material right on
ebay, ungrilled stamps, added fake grills, and made a lot of money by selling them on
ebay and other venues. We had him suspended several times, but a lot of fake stuff was bought by novice or uneducated buyers who never bothered to have an expert look at them until it was too late, if at all. So now they are showing up in the secondary market as some collectors sell off their stamps.
It is VERY important for collectors to submit stamps to experts when they are spending hard-earned money for their stamps if they are not proficient themselves in being able to identify altered or faulty stamps. To do otherwise is like throwing money down the drain. And any cost for expertizing will be more than covered at sale time, as buyers will have full confidence in the description when it is accompanied by a certificate from one of the recognized Expert services.
In this country, those are;
1. Philatelic Foundation;
2. APEX (American Philatelic Society);
3. PSE (Professional Stamp Experts);
4. PSAG (Professonal Stamp Authentication & Grading;
5. Weiss Expert Service.
All of them can be located online at their websites, easily found by doing Google search of any of their names. All also have submission forms, costs, etc online.