Seconding everything rccardr said above...^^^

With modern chain, the variable chain gap that you are going to be dealing with is not going to help this work "well".
Modern chain is sooo much more sideways-flexible than the vintage chain that the Crane was designed for.

In the end, getting this to work might come down to the marginal gains of much tinkering. Things like great cabling and fine-tuning of the chain-length and axle position can make significant improvements on many vintage setups involving very-wide gearing strategies.
For example, on a couple of recent vintage builds, I added some plastic noodle material at the metal cable guide above the bb. I then cemented it in place with enough glue to retain the short noodle in a fixed position. This had an out-sized effect on shifting feel, helping to get rid of the "elastic cable" sort of feel while shifting.