The hunt begins.
This is the sort of thing I'd be watching for at a train show/meet/flea mkt...another Weaver dummy unit/chassis of any road with good 'bones'.
OTOH, assuming the pilot castings at both ends are identical, you've apparently got a good one to serve as a master. Perhaps someone can offer you a casting service in metal (brass/zinc), or a 3D printed resin part.
Lastly, post a WTB/ISO plea. It's amazing what often can be someone's 'trash' to become your treasure.
Be patient.
BTW...If the remnants of your pilot are riddled with evidence of THE PEST...myriad cracks in the surfaces, etc....I'd be very careful in doing any further machining...boring, tapping, fastening. Dad's 1835 standard gauge steam engine acquired a split steam chest from Pestitis (Around 1950, I recall). A family friend did just what Richie C. suggested, the splice plate being quite substantial. I recall he bored/tapped four holes into the casting halves to attach the plate. It lasted one Christmas, then splitting again from one of the outermost holes. Apparently the whole casting was so pestified that it wouldn't tolerate even machining stresses. At that point Dad found a replacement steam chest casting...which survives to this day.
Let us know how it all goes. You're not alone...by a wide margin!...having this sort of problem. Unfortunately.
KD
