There's 30 days worth of data at http://www.otcmarkets.com/marketActivity/symbol-changes - but I'm really looking for the past 10 years, or 5 years if only that is possible. Any dice?

The closest I've come, and this is not really cutting it, is looking up a stock via Yahoo! Finance and seeing "TICKER is no longer valid. It has changed to NEWTICKER".

But that's not helpful; for example in the case of Skye industries, it used to trade as SKYY. But now SKYY tracks some sort of cloud computing ETF.

Any help would be much appreciated. Happy to pay for the data.