looks like a mess--an elect. motor hub (off ebay) would be a lot easer.
I think most of the derailers he used are for chain tensioning.Seem(to me)he ran his front sprocket to a cluster-small cog and a second chain second gog to the rear hub.this would shift as normal. the motor runs to a free wheel(he used a 5speed but a single would work)He most likely used BB cups on the jacksaft to add the freewheels.A lot of his chains and derailers could be eleminated by using an old schwinn that came with the freewheel in the BB.---sam