well I have a headache this morning so am wasting my day sitting here online instead of sewing. I did play around with the wheel on the motor and got the machine a tad quieter and i think actually cleaning it will help more. I know better than to tackle tearing it apart though when I feel like this.
I also found out that there were 3 model numbers used on this machine....NLB, NLH, and AHC. The most info I found gave a serial # of 471451 made about 1930. Mine is 909684 so I'm guessing it was made in the late 30's to mid 40's? I do have a call in to the company to see if I can date it.