Hi Joe,
I purchased all the cars retained by John Harris as well as all his spare parts directly from him in 1995. John was already retired and was living in Florida. He had trusted a friend to post his cars on eBay at the time. At the time I had long conversations with Mr. Harris.
Years later I wrote this that was published on line, about the relation between Mr. Harris and Pittman:
Team Pittman and the 6001
In late 1966, Pittman introduced a new motor specifically designed for slot car use. It had the general bulk of the Mabuchi FT26 but offered a much higher manufacturing quality. It used the arm of the previous 196B in a new steel formed can fitted with a die-cast zinc end bell and Pittman-style overhead brush assembly. The magnets were stronger than most out there, and as usual the quality was vastly above that of the Japanese motors of the period. There were two versions, one with flanged and sealed ball bearings (model 6001BB, $9.95) and with plain sintered bronze oilites (model 6001, $4.95).
To help popularize these new mills which cost nearly twice as much as the mid-size Mabuchi, Pittman formed a pro-racing team, composed of two hot-shoes of the time: John Harris and Mike Smith, both from the Chicago area.
John set to build the latest pro-trend chassis as seen on the east and west coasts, and attempted to qualify at the top events, but while the 6001 were decent motors, they did not have the legs (and the brakes) of a well set up FT16, and it was not long until Pittman withdrew their support.
Here are a few of these survivors sold to me by a friend of John Harris, now 86 and retired in Florida, which he trusted to liquidate his accumulation of cars and parts. The first car I purchased was this Mirage, and an inquiry led to the purchase of over a dozen cars and tons of spare parts:

The body is a Dynamic Mirage, with a Pittman sticker at the rear. The front wheels are rare Cox Lotus extra-narrow magnesium with Weldun tires. The rears are Riggen with black rubber. The driver is by Cox, mounted on flat black card. The car is completely original and was only cleaned from 35 years of atmospheric pollution.

The inline chassis is extremely neat and shows very good craftsmanship, especially the main rails going around the back and to the from axle tube, not so easy to do in one piece... The Pittman 6001 motor is affixed with two machine screws.
The guide is a Dynamic, the gears are Cox.

These other cars have a famous history of their own as they were shown and driven on the Johnny Carson Show, Johnny himself driving (and immediately crashing) one of them on a Revell track set in the studio.

The down side shows the Lotus and Lola T70 fitted with the Pittman 6001 motors, while the Lola T80 Indy car has a rewound Russkit 23 and the Ferrari 3-liter F1 has a rewound K&B "Jaguar", their version of the Mabuchi FT26.
John also had a whole range of modified stock Monogram 1/32 scale cars with vacuum formed bodies as well as home built ones.

Here is a page of a 1967 issue of MCR showing John Harris involvement:

At least, these cars, now relics of a fun past, did not end in the thrash can like so many...
Joe,
I also saw the auction that took place a few months ago with a whole new batch of cars. Frankly I am not sure of their origin since Mr. Harris is no longer with us. They could be his, that he passed along to someone, or not, anyway I copied the pictures of the auction but recommended to Scott at the LASCM to pass on the lot. I am happy that you have them now.