Schuylkill County had the marriage records at the URL I included in the email. Being creative in the spelling of MOLIUSIS helps.

I would suggest getting all the U.S. records before jumping off to look for records in Lithuania. You would need to know the church where they were baptized in Lithuania.

Get copies of the U.S. church marriage registers for all the siblings including John. They will likely be written in Latin but can contain their places of baptism, parents surnames, etc...

Tom