Mk2 bicoupler central attachment node + fairing

[Bomoo]

The idea is quite simple, really. What I'm proposing is a centreline attachment node for the Mk2 bicoupler (this thing)

that will allowed it to be mounted inline to 2.5m rockets, and that will generate an Mk2 -> 2.5m adapter fairing with sufficient internal clearance to accomodate likely motor choices (i.e. Lv909s, aerospikes, etc.).

The KSO mod, for example, provides something broadly similar to this, allowing the smaller 1.8m shuttle to be mounted inline with 2.5m rockets through the use of a special adapter. The implementation is slightly different from what I suggest, but the capability gained is the same.