Wow! That does look like a factory installation, to me.
If you can get another look at this one, see if you can get a pic of the full 'magic numbers' of the engine - they'll be on the top cowl, near the spark plug. 1974 would have been just before the 'Tractor x' series came out...
Cheers,
Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
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