Great info V12 - thanks very much for taking the time to add to my post with your experience.
I am aware of how rare the Mustang motor is. They earned a fearsome pedigree on the European circuit in the mid to late 80's, having put 3 members of the Italian team into the A Final at the '86 Euro's (before they started using Coyote's), and then qualifying second the following year with Umberto Pernice using his Coyote, ahead of Jamie Booth in 3rd with his CAT. Beating Jamie says a lot, but they actually got FTD, 2nd and 3rd qualifying positions in the 86 A Final.

- 49019420_10158074434761258_6468822923665735680_n.jpg (16.97 KiB) Viewed 3087 times

- 49019420_10158074434761258_6468822923665735680_n.jpg (16.97 KiB) Viewed 3087 times
I sent mine off to Glyn Ward for a rebuild - Glyn used to make BRM motors back in the day and was on close terms with Mike Reedy. He has fully overhauled the motor. The magnets were way off when he first opened it up, so he has re-aligned them for starters before zapping the can.
Flag should be pointing to the notch on the can.
He also skimmed and checked the armature. He reported that the inductance was the lowest he has ever tested for a 16Triple, with the stack length being right at the very minimum, although no laminate had been removed. It certainly seems to be the real deal. I have managed to gain some contact details for Umberto Milanesi, the infamous Italian motor builder, so I really need to bite the bullet and try conversing with him about these motors, although it will all have to be in Italian
I have also been in discussions with the TAG team driver Umberto Pernice, who told me the Coyote morphed into what became known as the Pro10 production kit over a period of time, with most developments ongoing on track through the 87 season. They didn't really start using the Coyote themselves in competition until late '86, and by the 87 Euro's they had more upright suspension as per the Pro10 and had developed the front one-ways, but there were also cars there with the lay-down front suspension set up still, and all cars were still called 'Coyote'. Umberto was the one who sent me his set of front one-way adapters in fact. He was running a special carbon fibre tub chassis made for him by Ferrari(!) at that time.
The car below from the '87 Euro's has more conventional upright rear suspension with long shocks, but still retains the lower front set up and the Coyote shell and bumper. The front one-ways meant they could use 'Tamiya'-esq three point wheel adapters, which is why many of the drivers then started using Polaris alloy wheels.
The one-ways are also mentioned on the tech sheet for the 87 Euro's A Final.
By this time they were also testing out prototype thicker, stronger wishbones (white on the team cars) again which eventually found their way on to the Pro10 when it was released. They also added the rear toe-in mod and anti roll bars which the team drivers had been running on their Coyote's for some time. I am now adding a few of these mods to my Coyote and Umberto has really helped me out with that. He helped me source some of the thicker upper wishbones and has also sent me one of their anti roll bar set-ups, but I haven't thought about fitting that yet (front or rear??) Still researching as we go, but getting there. Your info on the subject is therefore very much appreciated!