Hi Gregory!
I think you need some explanations to understand the situation in the past and also old documents you got from Estonia.
a) All official life on our island was in German (newspapers, church documentation, education, higher culture, theatre and so one). The Old German name of the island was Ösel (In some redaction Oesel) and our only city was Arensburg. Today the island of Saaremaa and the city of Kuressaare. Names were changed after the victorious Independence War about 1920.
b) Same situation is with local names. Historically they were used in parallel at the same time. Germans (they were mostly the landlords and other officials) used German names and Estonians (mostly less educated farm workers) used Estonian names for the same geographic places. Today only Estonian names are used.
c) From about 1850-ties Russia starts an official Russification campaign in the territory of Estonia. For this reason a number Russian orthodox churches were built in the territory of Estonia – also on our island. An official campaign was started for re-barbarization: from Evangelic Lutheran religion to the Russian Orthodox. With this act these people also got new names.
For example: if your Lutheran name was Karl, then in Russian orthodoxy the ew name become Kirill; or if your name was Gabriel, then the Russian church changes your name to Gavril. Also all newborn children were forced to get Russian style names. I believe your grand-grandfather Hints was member of Russian church.
http://en.wikipedia.org/wiki/Baltic_Germans
http://old.estinst.ee/factsheets/factsheets_uus_kuju/baltic_germans...
http://www.estonica.org/en/History/1710-1850_The_Baltic_Landesstaat...
Some links about places, where members of your grandparents were born.
http://www.mois.ee/english/parish/karla.shtml
http://www.mois.ee/english/parish/kaarma.shtml
http://www.mois.ee/english/parish/poide.shtml
Gregori Paul Alexander Who is this Gregory to whom you are "talking" here in Public Discussions?
Without reference or name tagging he will probably never read this post.
Saaremaa Island - Old Latin name Osilia (sometimes also Thule).
Ösel or Oesel is yes German name format.
Arensburg is and was official name of the Bishops Castle in Kuressaare. Estonian name Kuressaare and German name Arensburg have been in use in parallel for centuries (since 1563, when this town got City Rights).
"Names were changed after the victorious Independence War about 1920" - this is not true.
NB! During Soviet era 1952–1988 Kuressaare was renamed to Kingissepa and all Saaremaa County (Saare Maakond) was Kingissepa Rajoon (~ Kingissepa Region).
The reason for changing religion from Evangelic Lutheran to Russian Orthodox was not just the Russification campaign but main reason was in Western-Estonia was that "over-comers" had right to privatize lands (so former serfs of serfdom (slavery) got additional lands if they changed religion).
The names variation between Estonian first names (remained in everyday use) and Russian Orthodox names (used mostly in church books and official documents) is much bigger - there are much more variants.
P.S. The use of Gabriel and Karl by Estonians was very rare. These where typical German and Swedish names.
Lauri