1. Gillette - Ranger Tech - probably 1941. Just one year, which is why so rare. Later, they would start to produce the Super speed line, which would look similar to this one. So maybe this one is the grandfather of the highly successful Super speeds.
2. Gillette - Super Speed Flare Tip - usually a mid range aggression shaver that was super popular back when (50s & 60s). Probably shaves similar to the ranger tech.
3. Gillette - Fat Boy Adjustable - they made these for about four years, about '59 time period. This is one of my favorite vintage razors, because of its look and heft, and at the lower ranges, it is so smooth. Gillette changed to one we call the “Slim”, which looks similar, but has a slimmer handle and a slight change in head design, and made that one for a lot longer. So the Fat Boy, being more rare, is more valuable.

 

All of these razors have much better workmanship and materials that most modern ones created today. So many these days are just plated pot metal, and will usually break after a few years of use. And there are companies like Vikings Blade that are adding a story and marking them up super high.

But these that you have are brass at their core, which will outlive you.

 

As far as dating goes, most of these will have a date code at the bottom, under the baseplate. A letter will be on the left end, and a number will be on the right. The letter is the year, and the number is the quarter of that year.

https://www.badgerandblade.com/forum/wiki/US_Gillette_Dating_Information

Scroll down to the section: 1950-1988 (letter codes)