Evaluating the aesthetics of any discus can be tricky as everyone has different things they look for. Due to the angle of the pic you posted it's a little tricky to get an idea of the true shape of the fish, none the less here's my input.
1. The hard rays of the dorsal fin seem some what blunt in areas and uneven, they should form a nice smooth rounded curve.
2. The little bump at the base of the start of the dorsal fin seems pronounced giving the fish the 'hammered' look you mentioned earlier. You will find most Discus have this bump to varying degrees. Have a look at Wayne Ng's Angel Diamond line he breeds for example, they have a very pronounced 'bump', I personally like the bump ... but it should accompany a very nice rounded forehead and not be overly pronounced IMO.
3. The forehead on this fish seems to protrude a little too far for my tastes, IMO from the dorsal bump to the mouth should be a very nice outwardly rounded curve, this fish seems to be somewhat angular in that area. This is what is giving the fish the 'hammered' look, in conjunction with the pronounced dorsal bump.
4. From the chin to the start of the anal fin also seems rather angular too IMO, detracting from the nice round shape ... although it could be the angle of the pic. This seems to give the fish a slightly pointed look as opposed to nicely rounded.
The eye seems to be well proportioned to the rest of the body and the pectoral fins seem to be well positioned on the body. The caudal fin (tail) looks a little large in relation to the rest of the fish, again that could be the pic.
Overall a nice fish, although not show quality or 'A grade' .... 7/10
I beleive the positioning/spacing of his caudal fin in relation to his dorsal and anal fin are a bit off. This gives his caudal fin a drooping appearance (might be the angle of the pic).
He could do with a bit more anal fin (towards the front), which will help with giving an overall more rounded appearance.
He has a nice chin and eye, colour and pattern are all good.
#1 has the bump just before his dorsal fin, but it also displays a notch/bump in his head at eye level. It also seems have have somewhat a beak mouth instead of a nice smooth curve.
#2 Has a very 'Flat' head instead of displaying a curved/ rounded face.
#3 In my opinion displays the best shape and demonstrates a nice rounded face.
All the above fish shows excellent signs of growth (Extremely small eyes) and display great patterns/colour.
I won't even try to get into the more complicated stuff as I'm not anywhere near qualified enough to do that. I can only comment on the basics.
What is show grade and what is A grade? Are these the same?
I'm sure everyone will agree that show grade fish are very rare.
So what makes an A grade fish?
IMO an A grade fish is one which has a nice rounded appearance and does not have major flaws (bad gills, eyes, bent spines etc). They also have nice colour and are healthy.
You can call anything else whatever you want. I don't believe in AAA, AA+ etc.
In the REAL WORLD the albino alequer is probably at the lower end of an A.