I just purchased two of these, they are not vented however.  Probably OK since sealed.

Fit was perfect, great warranty, and now my main and Aux battery are the same make, model year.  I have a dual battery shore power charger which has kept my prior batteries alive for over 10 years.  Felt it was time to change out, as preventative.  When batteries start to die, it is hard on the alternator.  And with a dual system, probably a good idea for less than $200.

https://www.pepboys.com/bosch-premium-performance-battery-group-size-41/product/9073724/1984/VOLKSWAGEN/TYPE%20II%7EVANAGON/4-1900%20water%20cooled

Note: these batteries do not have a handle, so you will need a battery strap that fits over the terminals to drop them into place.  Also, there isn't a cover over the positive terminal, so took the one off the old battery.  (lined up good enough).

Jack R. 84 Westy.