Greetings Linda! You know a good deal about your ancestors. You have one request -- where were your paternal grandparents buried. If you know post the following information as well:  your parents' wedding date,  church where your parents were married and  photographer's name and address if they appear on wedding photo. Edite Talmanis name appears on the Internet -- contact her as she may know. Some corrections and observations follow:  It is not Alsknis but Alksnis (alder tree).  It is not Spaevnis but Spalvins with comma underneath the n and check mark above the last s. The meaning is diminutive form of feather or pen.  Of the threesome the only correct spelling is Ogrin  Prior to 1920 writeen Latvian language was Germanized.Sutta, Ogrin, Rudolff, Arvid and Rozental are all Germanized but more so would be Rosental or Rosenthal.  The other names are Latvianized version of Latvian language. In U.S. most Latvians say Anna Murnieks while most Latvians in Latvia say Anna Murniece (Germanized it is Murneek)  Talmanis, Sutta, Rudolff, and to my surprise Spalvins are all rare surnames. The other surnames are not rare.  You can find the progression of population of Riga on the Internet. From a small city primarily of Germans it became a large city of Latvians. This was result of the Industrial Revolution and that farm work is hard. An inhabitant of Riga born in 1880 most likely was born in the countryside and not in Riga. According to the Internet Margarita Talmanis was born in Plavinas, a city of 1000+-2000+ on the northern [left] bank of Daugava River about 65 miles from Riga. North and west of Plavinas is Klintaines pagasts. North and east of Plavinas is Aiviekstes pagasts. In Klintaines pagasts are small villages (group of homes) named Murnieki and Alksni. In Aiviekstes pagasts there is village of Laci. Those names are plurals of names in your posting. It is likely that people in your posting or their relatives lived in those villages.  It could be Mikins but check documentation.  A street address in Riga could be helpful.
Someone can help you find the information you want. Are you intending a trip to Latvia?