Does a 100% disabled Combat veteran get a break from the dues,as he tries to become a higher level of Mason?

No. However, depending on the Blue Lodge that the Master Mason is Raised, (Home lodge) The lodge may help him in some manner.

Also, Major General Henry Knox Lodge is for armed services folk. If you contacted them, they may be able to help.

Thanks for your quick response. As you know the dues can get expensive very quickly.