I know this is not truly concours-relevant, but the data may be of interest to the forum.
My harness refurbishment business just reached a major milestone: 500 underdash harnesses have been refurbished and sold to customers. When I started out in March, 2008, I thought that there might be sufficient need to make this a hobby business, defined by the IRS as having no consecutive years of making a profit. As of 2011, I had to register as a business, as the demand for these services was greater than I originally thought!
I started out thinking that the distribution of harnesses by production year would largely reflect two factors: how many Mustangs were built and the cost of reproduction harnesses. Mustang productions peaked in 65/66, declining all the way through 73. Reproduction harnesses start out at ~$500 for the earliest years, growing to ~$1000 for 1970. No reproductions are available for 71-73. I expected a reasonably flat distribution from 65through 70, with a bit higher demand for the later years. What actually happened was much different:
The biggest surprise is that 1969 dominates all other years, accounting for 26% of all of my work. The next highest year is 66, 67, and 70, each running about 13%. 1968 accounts for about 10%. I think this data is telling me that 1969 is by far the most popular year Mustang, and that the 71-73 demand is much lower than other years. We’ll see if this changes over the next few years.
Thanks for reading!