Thanks for the replies! To answer Betty Wont's question, it's not being used for a buffer or as a gain stage. Its use is pretty weird and beyond my limited circuit-analysis skills. Here's the schematic for anyone curious (the JFET in question is Q101 on page 2): https://pdfslide.net/documents/rockman-x100-and-soloist-schematics.html
I think I'll go with oeslicoalfin's idea of using a MMBFJ201 for now.
I think I'll go with oeslicoalfin's idea of using a MMBFJ201 for now.