Other than maybe the issue of battery life, Cooper likely would accept the modern versions of these sights, given their now-proven reliability.
As for a small, light, high-quality ESD (electronic sighting device, if you will, or "red dot sight" in colloquial terms), look up the Trijicon RMR-DI (not the regular RMR). And the 12 MOA triangle gives you a precise aiming point at the top point. (although there's the wash-out criticism of this sight when YOU are in low light and your TARGET is in bright light - I think this criticism is overblown and perhaps a non-issue in the real world, but you have to decide for yourself)
No battery reliance for this sight - so perhaps Cooper would have liked this one. Of course there are others sans battery reliance, too, but they are larger - Trijicon reflex sight, Meprolight, Leupold prismatic, couple others. Perhaps he would have been accepting of these.
HOWEVER, I still don't think he would have endorsed a 1X ESD for his Scout, simply because SOME magnification is helpful - very helpful in fact - for longer shots. There IS a happy medium for getting some magnification yet being able to still "see" simultaneously the target in the scope and the target in its environment outside the scope with the "other eye" - that happy medium is in the 1.25x to 2.75x range. I would argue that it's in the 1.25x up to 2.0x or maybe 2.25 power range. I only say up to 2.75 because the Leupold scout is 2.5x and the Burris scout is 2.75. While these are *OK* for kinda seeing the target with the "other eye", they're a little bit too much. The IDEAL is right about 1.5x or 1.75x or maaaaybe 2.0, right in there. A variable that goes DOWN to 1.25 or 1.5 and up to whatever (4 or 5) would be and is very nice, BUT then this violates the KISS principle of the scout rifle (arguably). So the best overall tradeoff to be true to the KISS scout principle is a fixed power of 1.5x (or if it exists, 1.75x). Second choice would be a fixed 2.0x.
Now that's if you MUST stick with the fixed due to KISS principle. If you go variable (going into pseudo-scout territory, leaving scout territory), as I personally would, I'd go with the Nikon Omega/Slugmaster/ Turkey-Pro in 1.65-5x36. There are several reasons why this is the PERFECT pseudo-scout (forward-mounted) scope. First, you can just leave it forever and always on 1.65 power and it's your ideal fixed power KISS scope (so I guess if you don't touch the dial, it's an actual scout). Heck, superglue the dial if you want.
. But if you just happen to take that 150 or 200 yard shot, dial 'er up to about 3 or 4 (you can't really dial to 5, because the eye relief goes down to just 5.5" at 5x, and you need at least 7 or 8" for forward placement - but it's still got 7 or 8" ER *easily* on 3 power, which is essentially twice as much as the low end 1.65). Other reason of course is the ER itself - It's got *up to* 13.5" on 1.65x and as mentioned, at least 7 or 8 left at 3 power. I think it still has 7 or 8" left at 3.5x, even. Now, you need to get the Nikoplex reticle. If you end up with one of the worthless BDC reticles, get rid of that junk - send it to Nikon to get a Nikoplex or anything but the BDC with the little non-precise circles.**
IMO, YMMV, and all that.
**Oh, incidentally, these scopes - the most versatile scopes ever made in the history of earth, have been discontinued apparently - mind-boggling - so order yours NOW from Natchez or elsewhere, folks! You will thank me later. They have enough eye relief to use them as a pistol scope, but really shine in the "scout" type placement. Yeah, yeah, the parallax-free setting is short (I think 75), but for their uses this is OK. It *should* be a little higher on a scout rifle (100 or 150 ideally), but for the purpose of a scout rifle, having a 75 parallax-free setting comes just within the acceptable range in my book.