I have the same outboard in Eska's own brand name, the lower cowling is a bear to get off, I suggest if you do what mahty suggest that you start buy taking the power head lose from the leg, you need the one base gasket to repalce but I tell you as a fact that thing will eat your hand working on the carb with the lower shroud on there...I just leave mine off.
I think mahty meant
www.certifiedpartscorp.com and look under vintage , have your sears part numbers and call Diann or Vern, drop names, Iboats...Eska Yahoo group etc etc....best price cheapest shipping & OE parts.
PS the ignition is a cheap fix if you do it yourself, still cheap if even if you have to send it to the guys at Eska yahoo group, I have the modules if you can solder.
DougS