I'd like to see you stay away from the electric pump as you're close enough to stock that the mechanical pump that was designed for the job is really the best way to go. You can try a rebuild - but if someone has been at it without documenting what has been done you may be throwing good money after bad. If you can return the electric choke, I'd buy a new 1406 so you can start with a known good part. Unfortunately, the 1405/1406 tend to run a bit rich out of the box and I can not tell you how many times I have installed .095 jets and 073 x 047 metering rods to lean things up a bit.

Let us know how you come out,
Glenn