sometimes some connections on the obd connector are missing too .... if you know the main chip under the blob you may find some firmware, but you do know, it was emulated on different chip(s)
I did find a very close copy of an original elm327 adapter, and i bought an elm327 v2 original chip, substitued it (the clone) and it works very well
some elm327 in metal casing where very close to the original designs, up to 1.5 version youll get the chance to have 90-95% of a cheap copy
Simply buy an original elm, thrust me i have 8 clones (wifi, rs232, ftdi based an other usb chipsets)
Some sellers say on Fleabay and Ali v2.2 versions, but when you do a software querry of the fw version they report 1.5