As you can probably tell from the "I need ID help with this" GLORIA EXERCITVS posts I've done over the past month or so, I've been cleaning and attributing coins from an uncleaned lot of (mostly) GLORIA EXERCITVS types. This one did well with just several distilled water soaks and some light brushing. There's even a bit of silvering remaining and a really nice turquois patina. Constantius II as Caesar Roman billon reduced Centenionalis (AE 3) Siscia, AD 336 1.38 gm; 16.6 mm Obv: FL IVL CONSTANIVS NOB C, laureate and cuirassed bust, r. Rev: GLOR-IA EXERC-ITVS, two soldiers standing, spear in outer hand; between them one standard; in exergue: ΓSIS RIC vii, p. 456, no. 254; LRBC 756; Sear 17710; Cohen 92 (var.) Let's see your examples of Constantius II or of coins from uncleaned lots that came out pretty well after cleaning.
Here's one I got in a batch of uncleaned coins many years ago. It was covered in about 1/4" of hard, black crud; I had no idea what was under it. I used electrolysis to clean it. It's one of my best success stories. This one was in the same batch and covered with the same crud:
Gsimonel, Wow. Do you have some before pictures. I really like the design of both the obvers and reverse of the first coin. Military designs in general I find enjoyable.
Unfortunately, no. I had no idea the coins were going to turn out this nicely. Had I known, I would definitely have taken some before photos.