Moller 71 - under seat  

So did those only have the black mesh then foam? No burlap straps in-between?

Earlier production chairs (like yours) would have had Burlap supports. Later chairs (I'm guessing 70's onwards) used the plastic mesh.

I believe Moller seat support chronology went from jute webbing, to rubber straps, to elastic mesh. If you're planning on using jute (a fine choice), make sure not to leave any gaps in between the strips. While gaps are fine for loose cushions on lounge chairs, the thin foam padding and tensioned upholstery on these Moller dining chairs will result in telegraphing of jute strap edges on the seat rails if there are gaps there.

I have the elastic/elasbelt  on hand.. any reason to not use those? I know Jute would be more 'authentic', but I also dont have a stretcher.  I know Im over thinking this. ha ha.

If I have this correct, Im going to use:

Dust cover--Elastic Straps--Foam--Vinyl (instead of leather.. I have young kids and these are our main dining chairs) and then some sort of tape to cover the edges. The only fabric material tape I am aware of is hockey tape.. that may work ok. 

Side note, I emailed Moller and inquired if they ever sold 'blanks' with no seat at all and as expected they could not confirm.