Industrial Output accounts for more than half the CO2 (and even more of the other major pollutants) in the US, add to this that transport is made up of various element, the major contributors being commercial transport and you will see that someone owning a classic car is pretty low down on the list of people we should be asking to give up their transport, particularly as a classic car will be more green over it lifetime as long as it is in use as the environmental costs associated with building a car etc outweigh its ownership by a large margin.
Now to your figures:
EPA (IPCC 2007) figures show that Global Greenhouse Gas emissions by source are as thus in ascending order:
Energy Supply: 26%
Industry: 19%
Forestry: 17%
Agriculture: 14%
Transport: 13%
Residential and Commercial Buildings: 8%
Waste and Waste-water: 3%
http://www.epa.gov/climatechange/ghgemissions/global.html
So I would question that asking someone to give up their classic car is really necessary when their are far more important areas that need far greater attention.
Having read through your claims, I find that they are not supported by the data..to begin with you have just give the US dataset, which differs from the Global and EU datasets..also there is no mention of the 90% personal domestic driving figures you gave, I think you are confusing them with the 90% figure given for the fuel type and Industrial Output is far in excess of the 15% figure you quote (I think you are looking at the CO2 Fossil Fuel figures only), which isn't in that data, it actually gives the figure at 20% not including power generation which would increase that to 52% (and that is for the United States, globally the figures are somewhat different as illustrated above from the same source data).
National US GHG figures:
http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html
In the 2012 Summary (same EPA source material) Power Plants (industrial) accounted for 40% of the US carbon pollution and 67% of direct reported emissions, far exceeding emissions from private car owners and significantly more than those who own Classic Cars.
Well DP's figures are pretty off..but that aside, I am afraid that someone owning a Classic Car is NOT entitled and is NOT the main source of Global Climate Change. In fact as the owner of a Classic Car he is probably more green than the owner of a Prius or the person who buys a new fuel efficient car every five years due to the innate environmental costs involved in car production and disposal.
As for hard truth: well that is simple...There are simply too many people, and that is what needs addressing..nothing more.