FYI, you have an error in your series 2 time line.
Apparently Vandersteen changed over to rubber surrounds some time during the 2c model run, so the 2c is the 1st model to use rubber surrounds. Some of the early serial numbers 2c have foam surrounds but later serial numbers 2c have rubber surrounds. My 2c #17750 and #17751 have rubber surrounds. On ebay someone parted out a pair of 2c with serial # 13620 and 13621 and the pictures clearly show rubber surrounds on both the 8’ woofers and the 10” active acoustic coupler. The auction # respectively are 171293055693 dtd 13 May 2014 and 301192896288 dtd 26 May 2014.
If anyone else has a pair of model 2c with rubber surrounds, can you post your serial number so we can figure out at what serial number the change over occurred?
LGW