Here's something I dreamed up while I was recovering from a back injury while vowing to never strain my back again by putting a pinball on its legs... I've put around 20 games on their legs using this, and it's still going strong...
1 hydraulic trolley jack
1 sack barra
About 0.5m2 18mm ply
0.5 bicycle tyre
Screws, various lengths
Nuts and bolts as seen fit
I actually made this over 15 years ago, not sure if I made drawings for it, but the below pics show it in action...
Not only does it get the game from vertical to horizontal with enough height to get the legs on, it can also be used to wheel the game around into its slot in the line up... obviously you can therefore also use it to wheel games out of a line-up to work on them...