Looks like the closest alternative would be 50/26T front with a 16/19 dual freewheel cog and a 27T cog on the other side of the hub with a tensioner

This would be 83 gear inches top gear and 43 low gear on 16T with the ability to switch manually to 19T for 36 to 70 gear inches. 27T cog would be cumbersome to set up but results in a 25 to 50 inches two-speed range