Main IC is accordingly to filename is CY7C68013A-128 (cheap). Small ICs are SN74LVC1G02 (74AHC2G08 is not need and was bypassed). Schematic is reverse-engineered from working device.
Firmware is there in file "iic" - it is for eeprom, as usually for fx2lp.
Small module is SJA1000 module, but need change crystal to 24MHz (it is more stable). Constantly powered. Isolation not used.