An amendment to my previous message.

I found nreverb.h in an older sources archive.

As for failure to compile Lptrkfns.c due to compiler error C1001 with Visual
C++ version 5.0, I was able to build this file and link consound by adding
the following line just after the #includes:

#pragma optimize("g", off)

This has the effect of turning global optimization off for only this file.