It's quite crazy... The core is a 3*28 wrapped in 38+2*28+2*flat(0.1*0.3) all wrapped in 38 again! The wire is on Amazon, not sure if links are allowed https://www.amazon.com/dp/B078PDTX1L/ref=cm_sw_r_cp_apa_i_UkIQDbP0H5WSH And I totally agree I had 22g round wire and it was still great from the Skyfall. :)
Stainless Steel Flux, 4 Oz, 200-850 F https://www.amazon.com/dp/B00V7UND10/
1/16" Gen Rep Silver Solder, .9 oz. https://www.amazon.com/dp/B000PSB6KU/
Those were what I used. But just about any stainless steel flux and lead free solder should work as far as I know.
I used Never Dull for all my metal cleaning needs, especially for anything copper. Almost every mech I own is copper and this stuff makes them like new anytime they start to get grimy, works well on contacts as well. https://www.amazon.com/dp/B0014IGAWO/ref=cm_sw_r_cp_apa_0PXZzbMSA8HG4
The italian super soft bottles are popular, but I can't find anyone that has them in stock and for a reasonable price. Still looking though.
That frankie clone bottle is horrible, but can be made semi-usable with an o-ring under the cap against the bottle's shoulder. Part of the problem with them is air leaks, and this remedies that. They are also too hard, so not much can be done about that.
I bought these square soy sauce bottles from Amazon and just drilled a 1/8" hole in the cap to feed the tube through. I used the middle size bottle. It's 1000% better.