If I'm reading the serial number right, (I had to enlarge the photo, but see it as AC045823) you have a model 66 commissioned February 1, 1928.
VERY nice looking machine, but I'd get rid of that pin strip on it...those pins tend to cause "pin rash" on the machines making scratches and weakening the clear coat.
To clean your machine. If the machine moves freely and makes stitches, you don't need to tear it apart! Go to You Tube and do a search for "MuvandFarve". Muv has some awesome videos there that show and explain how to clean these vintage girls without having to strip it down to nothing. Use sewing machine oil to clean the exterior of the machine, and then polish it with non abrasive car wax... TR3 Resin wax is tough stuff and will help to protect the finish and the decals.
Congrats!! You have a lovely machine for an EXCELLENT price that will last you AND your grandchildren a lifetime, and then some!
She's a workhorse and a half, you're so going to love using her! Whatcha gonna name her?