I see - you already asked this same question in the M715Zone.com forum - and also the responses to it.
It seems to me that there isn't too much demand for any such adapters, for a company to have them readily made.
I think the most logical option would be to swap the hubs to end with the 8-on-6.5" bolt pattern. Otherwise I would just recenter the HMMWV wheels.
(if I knew the backspace- and could confirm the bolt pattern (6-on-7.25" ??) of the stock M715 wheels, then I would gladly post an exact drawing of the modified HMMWV wheel, for this application.)
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