The attached image below is taken from a current Philatino.com auction for Worldwide and Argentina material which I normally receive
via the Delcampe (Luxembourg) website. There is a sprinkling of Guatemalan items in that auction, including this one, which is Lot #108 144 5376 with a +/- value of £7.80 ($10 USD). It is described in the catalogue as a, "Pair medio Real stamps, mint with gum and fine quality!" (Their exclamation mark).
I don't recognise these issues at all. They are not listed in either of my copies of Stanley Gibbons or Michel and I cannot find anything in my copy of Guatemala Vol I either. Is anyone able to elucidate for me?
Regards,
Mel West