Last Spring, I grafted Otterson to make the top tier of my Redlove™ Calypso™. It took just fine and grew about a foot. The scion was from Fedco. It was probably the thinnest scion I have ever grafted. Probably about a mm diameter. I did a cleft graft and could only align cambium on one side. I looked at the graft today. It sealed and grew completely across the cleft.
I doubt it will bloom this year. All I hope for is good growth so I can train it to form the tier. Otterson is considered among the deepest red flesh apples, dark red almost throughout the flesh. Reference. It may be disease resistant. I haven’t seen info about flavor or size. My guess is they are small and sour, possibly astringent. I’m growing it to add to other cooked apple recipes, such as pie, jam, apple sauce, for color and maybe a little flavor boost. If it blooms, I might (probably) do some mad scientist breeding experiments.
I just found more info about Otterson here,