Depending upon their condition (I haven't gotten my electronic bulletin yet), their value could be a bit less than in years past. I think it's largely due to the fact that people looking for a KF are older and want a car that can be driven or shown now. Cars that are of lesser quality then go begging for buyers. Add to that the soft economy and that helps drive down prices of all vintage autos in general...especially many orphans due to their unique collectability.
I've seen an increase in the number of estate sold cars lately and I see that trend continuing. In my opinion, if you're looking for a KF, there should be some good cars on the market and once the economy rebounds, they will be a very good investment.
