According to the Kenwood TM-D700 instruction manual, the "front panel mounting bracket" parts are: J29-0663-XX and J29-0664-XX. One part is the piece that the head snaps into and the other is the mounting base.
From the Kenwood TM-D710 instruction manual, the "panel holder" is J29-0663-XX and the "panel bracket" is J29-0707-XX. I believe "panel holder" is Kenwood's terminology for the piece that the head snaps into.
I know for a fact that a D710 head will snap into a D700 "panel holder" because I've done it.
My suggestion would be to contact either of the Kenwood parts depots (see
Kenwood) to see if you can buy the part. I just did a search on PacParts web site and found the J29-0663-13 in stock for $6.66.
As for Lido mounts, I had one that I was using for a GPS receiver and I wasn't impressed. The mount would not retain tension on the swivel part of the mount so the GPS receiver would not stay upright. I switched to a RAM mount and find that it works much better.