These are a coupple of versions of the OEPL firmware I've compiled for cerrtain Hanshow Nebular 350 tags. Hanshow Nebular 350 (SER 2 M3HG).bin is for tags that have the M3HG code on the back and serial number beginning with 2 may work forr other early serials but not sure). it is jsut the standard OEPL firwmare compiled for the Nebular 350 tag but with an alternative pinout set in main.h. Hanshow Nebular 350 (Ser 9 M3HG).bin is for tags that have the 'M3HG' mark and serial numbers beginning with 8 or 9. These tags use a completely different panel (JD7667) and required significant modification to the existing code to implement. There is no init screen set up for this panel currently so make sure that you try sending something to it from OEPL to see if it works or not.

I am planning to submit a PR to OEPPL for the JD7667 panel integration soon.