Quote captain0ldy0da:
should I seek to cosplay as the SS more I will definitely consider buying a replica of the real one

DANGER WILL ROBINSON
Ok, first question...Why do you need to be a Nazi at all?
Since you're doing an original character, surely you could base the design and even the uniform on Kronen but move AWAY from the Nazi symbology?
Plus, if you're going for Steampunk, you're almost 40 years too late, style wise.
Dieselpunk focusses mainly on the era of diesel power, so you're looking then around the World War eras.
As far as Nazi stuff in cosplay goes...Yes I've seen it done, hell, I've done it. I played Herr Major from Hellsing (the leader of BOTH the costumes shown above as examples of it being part of the costume).
Saying that, if people get offended, you don't really have much to say against it. You're taking highly offensive material and taking it into a public place where it is unexpected. If you run into someone who had a relative die in a concentration camp or was a survivor, you'll have A LOT of explaining to do and no real leg to stand on.
The difference between all of the characters shown above and you?
1. They were stylized. If need be, they could remove the necklace or the armband. It was easy to do so and I know a few of them who did just that.
2. They didn't have it woven into every part of the costume whereas you're basically going to be portraying someone who's job it was to run concentration camps...
3. Most importantly. You don't NEED those things. You're creating a character. They were playing characters who had those things as part of their costumes. People may well think you're some sort of sympathiser or glorifier of the Nazis. I've seen that happen before.
All in all, I think go for it if you want to. But personally I think it's slightly bad taste. It doesn't fit into Steampunk anyway as it is entirely the wrong era. Steampunk is VICTORIAN in nature. Sure, modified, but definitely based on that timeframe.