Hi Eric,
Yes it is E&I.
Yup the secondary is on the outside.
The winding unwinding part should be fun. The wire must be 3,35mm in diameter 10 SWG. To make a loop of 3,35mm wire could be an issue. I think I will make two seperate winding and terminate the 0V connection outside the winding, could be neater
.
I run a business that makes enamelled wire, I think I will get them to run a couple of meters, of the correct size, through the enameller at a reeeaaaal slow speed so that it annealed to death. That will make winding much easier.
Cheers
Andrew