The 7070 is one of the choices on KM's list of remotes, so I'm pretty sure someone has used JP1 with it (I had never heard of it).

As for the cable orientation, you might get a better answer in the JP1 group.

Did you buy or build your JP1 cable? Do you know which corner is pin one in the cable's connector?

The remote's connector usually has some special mark on the PCB around or near the pin one corner of the connector.

If you identify pin one on each, they go together.

If not, I've never heard of anyone frying anything by using the connector backwards. Lots of people try it backwards and then try it the other way. For extra caution you might try without batteries in the remote for your first tests before you know the orientation. JP1 usually works both with and without batteries, but on some combinations of printer port an remote it might work only with batteries are only without. Try both ways (all four ways if you don't know orientation) but try without batteries first.