You need to water mark it. However, I would say, the coils are the most faked of all the Washington's. If you're new to stamps, get some lighter fluid (Ronsonol) and a dark dish (black) that put the stamp face down as you have it in the last image. Pour about 1mm of fluid in the tray with the stamp, and look for evidence of a single line USPS watermark. The perf looks suspicious to me, so there is a strong chance this is not a genuine coil.
Cheechq, Welcome! You are looking in the right place on the stamp. Following along with Don's link to the stampsmarter site, the extra shading line in the ribbons makes this a type III. Beyond that you will find 2 possibilities depending on the presence/absence of a watermark in the paper. I won't spoil the fun of you taking these next steps. Secondly, your coil has perfectly genuine perforations. I see no fakery. Your stamp passed through an affixing machine which used a knife to cut the stamp from the coil roll and stick it to the envelope. The knives of these affixers almost always cut at a slight angle to the perforation row leaving the perforations increasingly longer or shorter from top to bottom. Note the smooth cut appearance to the perforation teeth rather than fuzzy torn ends. Evidence of the technology at that time.