Thank you everyone.
Just an FYI. In that picture I was spreading the crack open just to highlight it.
I have spent the day cleaning it with oven cleaner. The wood is clean now.
I spoke to a gun smith in town. He can not get acraglas. He said he uses Gorilla Glue and has had super success with it.
He suggested drilling a little hole at the end of the crack, the radiusing will stop it from spreading.
I tried with a clamp, and lightly clamped it. I don't think I am going to need too much pressure at all. The sideplate fits nicely.
So, after it thouroughly dries I will glue it.
wish me luck.
Pietro