Rob,
Looks nice!! but why did they took it apart in the first place??
In the older photos you can see it has a real late "Harley" style airfilter on it, probably from an Indian 741 it should have the civvy version, much easier and cheaper then the tall round one that I have (appx. $1200.00) and you don't need the special inlet tube casting.
Have no idea whats missing on the sidecar wheel as the parts books don't cover the sidecar, but have an Indian 340 p/l somewhere, will look in there if I can find it, they had the same sidecars.
Speedo's are indeed pricey, but so is everything Indian, I have found out!!
This is the Speedo (Corbin) that you need, NOT the same as 741! (see below)
There is a guy in Canada that does real good work;
http://www.speedoshop.net/?p=productsList
Cheers,
Lex