Here's a video further explaining and demonstrating the tool:

An adjustable router plane, inspired by the one designed by Paul Sellers, but can accept a chisel for the cutter, and with ergonomics similar to the Veritas large router plane.  

This plane is designed to accept a 1/2" or 12mm chisel as the cutter, but I've included a .step and a Freecad copy of the insert so you can edit it to fit whatever width of cutter you want.  It was designed as an insert, so that one can customize for different cutter sizes and not have to print an entire body just to swap out to a different cutter.  In case anyone wants to make their own wooden insert instead of printing I have also included a template drawing of that part. 
 

A clamp on part provides the engagement with an adjustment wheel, so no notches are required in the cutter like in Paul Sellers' plane.  Two versions of this clamp are included, one for thin chisels, and another that should accept a square cutter or a mortise chisel.  If a depth stop is desired, just print a second clamp and install it below the one engaged with the wheel.   Users may wish to add a wood base, so insert nut locations were added for four attachment points 130mm X 54mm  centre to centre measurements.  A .pdf template is included.  All the adjustments, clamps, knobs and nut inserts are designed around the same threads.  There are two versions, one for 1/4"-20 fasteners and the other M6.  For the main adjustment screw I used a 4" carriage bolt, but a bolt about 3" or 75mm is probably ideal.  For the clamp knobs I used 1-3/8" bolts, but anything from 1-1/8" to 1-3/8" should work fine, and for the metric version that would be 28mm-35mm.   The chisel clamp bolt can be nearly any length greater than 1/4" or 6mm.

I used PETG with 15% infill for all the parts, 3 perimeters for all but the clamp bar where I used 7.   

Prints without supports.