OEM rally rim stamping codes

[p7387]

Hello:

Any idea how to decipher the stamped codes on OEM rally rims.
Specifically date code?

stamped inside rear half
--------------------------------------------------------------

6      17   81    15x8                 jj       t        h
038               made in USA       mw    dot      o(with slash)



stamped on rear mounting surface
---------------------------------------
m4    d    241


stamp by valve
----------------
MI   6   17   CK

thanks