Ron,
Nice one.
Do, however, please please be very very careful moving it around as it could all come crashing down!
The loco sits well beyond the casters, tipping point, thus making it potentially unstable if care not taken.
I have found that out to my cost, and would suggest that you extend the base of the scissor stand to get the casters outside of the loco's O/A dimensions.
A similar principle applies to passenger trolleys at club tracks, except in this case the seat of the trolleys need to bear on the axles, but within the wheel track, when pivoting which happens as passengers get on and off, fully covered in ME many many many years ago.
Geoff – 'Felt' blown off of Summerhouse roof!