Exiv2

Hello All,
Just obtained the subject lens, and tried to find the lens ID code for it.
Using exiftool, as follows...
[terry@localhost 18-300-sigma]$ exiftool IMGP0382.JPG | grep -i Lens
Lens Type : Unknown (8 34)
Lens F Stops : 8.5
Lens ID : Unknown (8 34)

I interpreted this code as 0x8034, and added this code for the lens to my local source and built, but using exiv2 as follows...
exiv2 -pt IMGP0382.JPG | grep Lens finds nothing.
Have I misinterpreted the code as given by exiftool, or is there likely to be some other problem here?

Cheers,
Terry