I feel like I'm repeating myself (again)
1984 kick only - electric start engine conversion. Due to the lack of clearance of the output sprocket on an electric start engine and the older frames this is not possible without changing the output shaft with the one out of the kick only engine. Are you really that bothered?
It would just be easier to get an electric start bike
The other way round - adding a kicker to an electric start bike is easy like said before. Half an hour is possible to do it all (if you've done it before and have all the bits).
I do have all the bits and they are available to whoever wants to buy them.
The only thing I can't help with is the decompressor that is at the top of the engine. Due to yours being electric start they wern't machined to take the mechanism. It's not a big deal anyway - decompressors are for girls!!!