We'll have to identify them from the model numbers, when you've got those. The 1981 and before will have breaker points, while the 1982 onwards will have Magnetron (breakerless) ignition. With regard to which way the starter cord comes out, my 1976 Victa/Briggs not only has the engine oriented so the vertical starter is at the front, it also has a big sticker on the top-front of the base, saying "Put your foot here, stupid" or words to that effect. Some of the very old mowers (Turner was an example, as I recall) used to have a cast-on grid there, probably for the same reason.
The Tecumseh may be one of the late type with model number beginning with LAV (Light Aluminium Vertical), which seems to be held in low regard by those who've worked on them. I've never done so myself, and am fairly pleased about that. The good news is there is a full workshop manual for those engines in the parts and manuals section of this site. The bad news is that Tecumseh went belly-up a few years ago and the availability of parts is becoming patchy.
