A little more digging produced the following :
SHOP MANUALS
1966 Comet, Fairlane, Falcon & Mustang - No reference to Green Bulbs for MN & WI
1966 Thunderbird - Notes that 1895G is required for MN & WI
INDIVIDUAL YEAR MPC
1965 - No reference to Green Bulbs for MN & WI
1966 - No reference to Green Bulbs for MN & WI
1967 - No reference to Green Bulbs for MN & WI
READY REFERENCE CATALOGS
1966, 1967, & 1968 - While none of the three show "Applications", all three list the 1895G Bulb
FORD SPECIFICATION BOOKS
1966 - Shows 1895G for Thunderbird only in MN & WI
1967 - Shows 1895G for Econoline, Bronco, Thunderbird, Mercury Intermediates, Falcon, Fairlane and Mustang
1968 - No reference to Green Bulbs for MN & WI for any 1968 Models.
TECHNICAL SERVICE BULLETINS
August 1965 - December 1968 - In looking at each TSB during this period, there was no reference to Green Bulbs for MN & WI.
The only other thing that I have that I can think to check are Shop Tips from 1965 through 1967. I will go through them later.
Bob