I finally have an update related to my ancestors. After returning to the US, I was able to find the kamon, family crest, for my mother's family. My paternal grandfather had the crest on his tombstone.
I sent the picture of the family crest to Hiroko from Patternz.jp and she identified it as the Fuji-wa ni kikyo that you see below. We figured it was the bellflower (kikyo), but I never thought about asking my Japanese aunt. She knew it was the Fujiwa ni kikyo when I met her. I also learned that my ancestors were retainers in the Saga (Hizen) domain, not in Karatsu as I originally thought. The Matsunagas in the Saga region are said to be the descendents of Matsunaga Hisahide.
Originally I thought all the Matsunaga clans in Kyushu used the tsuta mon as below. Turns out that there were other family crests there were used as well including the Ivy (Tsuta) family crest.
The descendents of a famous Buddhist monk, Matsunaga Kuen, used the following ginger (myoga) family crest. He was said to be the younger brother of Matsunaga Hisahide. This crest was given by the Ryuzoji clan who ruled Hizen until the last head of the clan died.
I will update more in a couple weeks. I am a bit jetlagged still.