Hi mate. Unfortunately, other forums are quite anal, and MORE geeky than this one. To get any reply from that site is an achievement. There are repro items scattered about, but oddly, the whole 'repro' issue seems to concern MOTU collector far less and is almost seen in some quarters as normal. I'm not aware of any weapon testing that would help sort the fakes, but certainly rough joints etc would be a dead give away. There are sites out there which show step by step instructions on making 'hot glue gun' moulds, which I imagine would be reasonably easy to spot. Many of the repro items are parts, like the chains from snake mountain which were moulded in a harder plastic than many of the weapons.
The He-Man.com site does have a decent archive section, similar to RS.
To be honest, there are only a very few weapons which MAY be hard to get hold of. The others are so easy, you should be able to buy with relative confidence.
Neil