Re: Of the scopes pictured, which is right on a M40?
Pictures 1 and 2 show a first gen Redfield 3x9 marked 1 inch tube, this scope in anodized green, not in gloss or satin black was correct for the USMC M40, link to one on GB for sale,
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=173774913
Pictures 3 and 4, are a definite no, don't think that Redfield was even made in Denver.
Picture 5 shows a second generation Redfield 3x9, this scope in anodized satin black is correct and was used on the USMC M40, an example is pictured below
Picture 6 shows a Redfield accutrac, these were not used on the USMC M40,
Picture 7 again shows a second gen Redfield 3x9,
The correct reticle was fine crosshairs