Prompted by some sleuthing by Steve Bloom, here is what I have managed to discover about Mr. Mcintyre's life in his pre-Denialist days.
Sometime prior to 1998, Steve was an employee for Noranda, a mining company which, at its peak, had offices in 18 countries. However, by 1988 he had left the company, for in that year he helped found Timmins Nickel, a company in which he still holds the position of President (see here, though to view the full story you must be a Northern Miner subscriber). By the early 1990s, Timmins Nickel had developed two mines and employed 120 people, and you can find the occasional brief news story on them in places like American metal market. In 1991, Timmins Nickel acquired a stake in a project run by Dumont Nickel, a company for which McIntyre also served as President.
However, in 2002 Mr. Mcintyre was given the old heave-ho at Dumont:
Mr.Steve Mcintyre, who has been President and a director of the Company since 1991, has resigned from those positions to pursue other business interests.
Now, "resigned...to pursue other business interests" is often Corpspeak for "fuck off and die", and while it would perhaps be inaccurate (and maybe libelous) to characterize McIntyre's years with the company as a legacy of failure, it is clear from these two documents that the company had struck dust at a number of holes early in the new millennium.
As I say, you still get hits from 2007 for Steve and "Timmins Nickel" in the Northern Miner, so when he claims to still have some personal business holdings, this is probably what he is referring to.
In addition to all this, and as noted in his wiki Bio, Steve until recently served as a "Strategic Adviser" to CGX Energy Inc. and the Northwest Exploration company, two companies engaged in oil and gas exploration.
McIntyre's wiki Bio also claims that he served as "policy analyst at both the governments of Ontario and of Canada." While I have been unable to locate any documents confirming this, there is a record on the Ontario Government website of Steve's 1991 testimony to a legislative committee re. Bill C 70, "An Act to amend the Employment Standards Act to provide for an Employee Wage Protection Program". In his presentation, Steve complains about liabilities for mine directors, bitches about civil service wages, trash talks unions a bit, and whines about environmental regulations.
So, while none of this information is earth-shattering, it does help slot Mr. McIntyre rather neatly on the ideological spectrum as a small business Conservative with interests in the petroleum industry.