This jig serves much the same function as the stock jig supplied with the LittleRat.  The difference is that this one will more securely clamp wider stock and there is no offset induced when the stock is clamped.  I found that with the original stock clamp, the clamping action would draw the stock away from the face of the jig by about 0.008".  Most often that does not cause a problem but I wanted to see how this design would fare against it.  After I've used the jig a bit I'll post my evaluation.

The router base has been removed from the jig for clarity.

This is a back view of the jig.  The jig is comprised of three main parts.  The base which is attached to the sliding carriage is made of 1/2" MDO plywood with a rebate profile on the back to stand proud of the extrusion a bit.  The base is attached to the carriage using two original 8mm x 1.25 threaded holes and two new 1/4-20 holes that I made.

Attached to the base is a finger jointed box open on the back but with a plywood face.  This is attached to the base with some 1/4-20 screws threaded into the box.  The face of the box does not meet the extrusion, there is a sawdust relief.

The clamp bar slides back and forth to clamp stock of varying thicknesses,  It's about 1 1/2" square with two 1/4-20 threaded rod ends captured in it.  The box has a groove to accept one end of the rod and the base has another.  This keeps the clamp bar in basic alignment with the box.

I've left room on the back side of the jig to allow for a cursor to be added later.