Okay, I hesitated to answer at first, but I guess my first hunch was correct; cold water, woolite! I confirmed this by conferring with some of my reenactment buddies. This is what they have to say.
Wash your wools in Woolite. You can either wash by hand or the gentle cycle in your washer. Use COLD water. If you do wash it in the machine, use an extra spin at the end of the cycle to get out the most water you can, then hang dry. A lot of the guys then hang them outside if possible.
They are saying that you might get some shrinkage, but that is to be expected.
They say most cleaners won't touch old uniforms (as you stated) because of the liability. You can see why. Some will do it, but only after you sign a waiver.
Hope that helps ya.
Proud Daughter of Walter (Monday) Poniedzialek
540th Engineer Combat Regiment, 2833rd Bn, H&S Co, 4th Platoon
There's "No Bridge Too Far"