[GreenKeys] 28 tractor feed conversion?

[Nick England]

 Howdy men - I'm slowly moving forward with my triple 28RO "waterfall"
restoration. This thing came with two tractor feed typing units (and 1
friction feed).
photo - http://www.navy-radio.com/tty/waterfall/IMG_3663.JPG
more photos - http://www.navy-radio.com/tty/waterfall.htm

I am in need of learned counsel from this august group - should I
a) try to swap the tractor feed typing units to someone who
needs/wants them? Anyone interested?
b) try to replace the platen mechanism with pressure feed style?
Anyone got any spare partss?
c) try to find some of that oddball sized tractor feed paper (surely
an impossible quest)

As always, many thanks for the interesting and knowledgeable comments
that abound on greenkeys
cheers,
Nick K4NYW