Regarding the ALTERNATIVE FUELS and FUELS TAX question.......
In TEXAS, there are MANY good reasons to register your Historic Vehicle as a FORMER MILITARY VEHICLE.
Legal Disclaimer: I am NOT an attorney, and I am NOT sharing LEGAL ADVICE, but in fact am sharing what I have been advised by LEGAL COUNSEL as it applies to my own specific situation. Your circumstances may not be the same as those described below.
IN TEXAS, there is a "TOKEN FEE" of just $10.00/year for registration (this is simply a "paperwork charge" as NO LICENSE PLATES are issued, etc.). The Legislative Debate that resultied in the creation of the FORMER MILITARY VEHICLE (FMV) classification of registration based its reasoning on the fact that ANY ANTIQUE VEHICLE (of which FMV's are a subclass) is, first and foremost, an ANTIQUE that just happens to be able to be moved on the public highways under its own power. It is EQUAL to a Grandfather Clock, Grandma's Old China, or a Ming Vase... just that you don't need a separate vehicle to move it, you can just drive it between "exhibitions".
Again, IN TEXAS, Antique Vehicles registered as FORMER MILITARY VEHICLES are EXEMPT from any form of INSPECTION (as could be conducted on any other vehicle) simply because, by LEGAL PROCLAMATION of the TEXAS LEGISLATURE, accepted and endorsed by the TEXAS DEPARTMENT OF MOTOR VEHICLES though its issuance of a FORMER MILITARY VEHICLE registration, your FMV is an ANTIQUE COLLECTIBLE.... NOT MOTOR VEHICLE.
THEREFORE, it is legally defensible that ANY operation of your TEXAS FORMER MILITARY VEHICLE is an EXHIBITION of its APPEARANCE, DESIGN, PERFORMANCE, CAPABILITIES, TECHNOLOGIES, GEOMETRY and FUNCTIONALITY. This would include its use to haul NON-COMMERCIAL cargo (from Home Depot or to the Dump, etc.) or its USE OF ALTERNATIVE FUELS as EXHIBITONS OF ITS PERFORMANCE CAPABILITIES AND TECHNOLOGIES. FURTHERMORE, since in the State of TEXAS, a FORMER MILITARY VEHICLE IS NOT A "MOTOR VEHICLE" (remember, it's just a plain ol' ANTIQUE") in the eyes of the TEXAS STATE LEGISLATURE, any attempt to enforce MOTOR VEHICLE FUELS TAX LAWS would in itself constitute a CRIME by the citing OFFICER as a MISAPPLICATION OF LEGAL AUTHORITY provided that he/she is so informed at the time of attempted citation. The citing OFFICER could be prosecuted for, and responsible for ALL COURT COSTS resulting from, overstepping his/her authority in such a circumstance.
CONCLUSION.... We (me and my wife) can run WHATEVER FUEL that our Multi-Fuel Engine equipped M35A2 registered as a TEXAS FORMER MILITARY VEHICLE will burn as an EXHIBITION of its DESIGN, PERMORMANCE, CAPABILITIES and TECHNOLOGIES without fear of citation, prosecution or harassment by misguided Officers of the Tax Laws.