Cross reference shows your 143 . 973505 crosses to a Tecumseh engine H35 with one of these spec numbers. 45675Y 754294A 754291
Magneto number I came up with is 611025.
Points number I came up with is 30547A
Condenser number I came up with is 30548A
I have to ask if you tested the coil yet, as most time I find the points and condenser are bad, not the coil. I hope you have not removed the magneto assembly yet, because reinstalling it is not easy as it must be timed. Please read this manual about ignition systems before proceeding.
https://www.mymowerparts.com/pdf/Te...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf
Also, I would never purchase ignition components from Amazon or FleaBay, you never know if they are good and cannot be returned.