Thats precisely the road to go down
if only one remote works on them both, the remote is at fault - try changing batteries first.
if no remote works on aspecific box, but both work on the other, then it is time for a reflash. If a USB stick with OpenATV on doesn't flash it, then you need to tell us what stage you are at, we'll talk you through it.
as for the fact that Wooshbui;d is out of date - that is true, BUT, I have two boxes here with OpenATV 6.2 (If I recall correctly) and Wooshbuild and they both work perfectly well, if something goes awry, I just flash with the old ATV , then WB. I don't know what bells and whistles I am missing, but I don't need them. (unless someone can convince me otherwise)