FWIW, if you have, or can get a remote from the 700 (and I presume the 720) it will work for the 740.
Another idea, if you can't purchase a new one, is to find a learning remote. Providing you can find and borrow a 7XX rmote from someone, you just point them at each other, push the buttons in order, and the learning remote "learns" the codes.
Yet another idea if you can't purchase, ask iFly/Adventure Pilot if the remote is a repurposed remote from another commercial device (TV, VCR, DVD, Stereo, etc.), and what brand and model, then get a programmable remote and set it to that brand.