Hey Big Daddy Sleipnir!
I mostly wear my hammer "where it wants to sit" (i.e. wherever it falls - I'm female, so half the time my neckline is low, and half the time it's high). It's not an issue if it touches my skin or is covered or not, 'cause I have a tat IN my skin for all to see. The only time I make a point of wearing it on the outside of my shirt is when I go to my mother-in-law's, but that's cuz I'm a shitdisturber.
Pagan:The meaning of the wolfcross is, as you pointed out, somewhat of a mystery. Some scholars think it is a fusion of the two religions (a cross and a hammer coming together), while others think it is an asatru hammer with the sort of "totem animal", the wolf, on it. I assume you have heard about beserkers (bärsärkar), whose "totem animal" would have been the bear. There was also a similar group of frenzied fighters with the wolf as it's "totem animal". This cross could have been favoured by someone like that. HOWEVER, the cross looks more like a crusifix than a hammer, and so does the decoration in the centre, with a very typically Christian shape ("formgivning"...crap..it's too early in the morning for me to be bilingual). BUT it is also most certainly not facing the right way if it is a cross (I am not sure at what time an up-side-down cross became a symbol for Hin Håle, so I dunno if a Norseman would have known that it was "his" symbol), and in any case, since Christians do not recognize more than one god, in today's world, one would have to use it as a pagan symbol by default.
Pyaemia: Check out Kalevala Koru (Google it - many distributors). They have really good quality jewellry of the historical replica variety. Pricey, but worth every cent. Silver is the more historically accurate material. In North America, Raymonds Quiet press has given the best service and quality for me so far in brooches, pendants, armour, knives and so on. They are also replicas.