1970-74 - Gen1 (vintage)
1970-74 spacer - may combine post-1970's gasket with this spacer to form a thicker gasket - Gen1 (vintage)
1974-2000 - Gen2 (PreMillennium)
2000-2008 (non-ribbed Version 1) and some after 2008 - Gen3 (Millennium) and Gen4 (Stradivari)
2008-2010 (ribbed Version 2) and some after 2010 - Gen3 (Millennium) and Gen4 (Stradivari)
Created 10-MAR-2020 | updated 11-FEB-2023 | BCP