The Lionel caps showed up today and their leads are only 3/8 inch long - not too long for the spot where they have to be soldered to the PCBA nubs; definitely will take 3 hands. I see why Sinclair located the cap where he did; it is elevated enough to easily miss the flywheel. Here they are:
Gunrunnerjohn, you mentioned these alternative caps below; would you happen to have any and the lengths of their leads?
It's a 4.7uf 50V bi-polar capacitor, a cheap place to get it is Digikey as Lionel will have expensive shipping. Nichicon CAP ALUM 4.7UF 20% 50V RADIAL, 28 cents each. Shipping for small orders from Digikey is only around $3, and the ship very fast, usually in a couple of days you'll have your parts. You can have a few for around $5 total. 
