Delrin rudder mount insert broke

I have an 18ft Heritage Expedition XL SOT sea kayak. The rudder mount insert broke and knowing the part is most certainly unavailable after doing some searching,… I am buying a small delrin plastic block and will be fabricating the piece. It has three inch long 3/16" longitudinal grooves where the rudder control lines slide. Don’t really have access to a mill or machine shop for such a small part. I suppose I could carefully set up a circular saw and do a very shallow cut. Sure would prefer doing it by hand though. Also it has a 5/16 internal threaded hole where the rudder mount stud is screwed in. I will be drilling and tapping this but am a little unsure about the potential for cracking and breaking this small plastic part when doing so. The hole will be drilled and tapped in a 3/4 " thick piece of delrin on its edge so the sidewalls will be quite thin surrounding the hole. HMMM. Anyone have experience working with delrin?

Delrin is pretty tough. It is used for
harpsichord plectra, for which it must endure both carving and thousands of twanging plucks. Just go easy and keep the piece cool and probably you’ll succeed.