Marie, fortunately in the USA you will likely have a choice as to where you want your fish entered- ginrin A or gosanke classes. In a Japanese or ZNA show this decision would be made for you!

In that case they will count the rows of ginrin ( at least three either side of fish) and direct the fish to ginrin A or kohaku. But honestly I have seen a lot of tamagin in two rows each side of the body that seem to be an exception to this rule at benching time. Your now 'not matsunoske gin' is best as a ginrin competitor and your tamagin can be entered as either. But I suspect it is a better kohaku than a tamagin. Now having said that, judges can be 'lovers' of the rare tamagin and it might just carry the day?! This is the fun and excitment of the competition!
On your 'matsunosku', yes, that is betagin, nice and subtle and preferred to daiyagin ( hiroshima Gachagin or cracked glass gin) but both are special on the right fish. My preference is to see betagin like yours on gosanke as it is a lovely effect and doesn't destroy a gosanke's beni color tones if the quality of the beni is also high. And I like daiyagin on solid fish, especially black fish, green, yellow and platinum fish as the fish can seem to handle the surface glitter effect well? In other words, the betagin can add to the dorsal patterned fish and the daiyagin can make a plain solid pattern more interesting.
The one thing that isn't appreciated by anyone is messy daiyagin as it is uneven/disorderly and light ( not deep in scale) and draws attention to it's imperfections. Hope this helps? JR