Rocky Mountain Stratos questions

[shedobits]

I have a chance of buying this in the new year, my plan was to strip and polish it before a rebuild but it has two cracks around the seat clamp junction.
Can it be repaired?
Reading up on this model I believe it should have a 27mm seat pin but a 26.8 is fitted, could this be the cause of the failure?
What do the experts on here think?

 

[vtwinvince]

I have a Cirrus with the same problem, though not as bad as yours. I had a welder run a bead on both sides of the crack, but of course with heat treated alu this is always a 'ghetto' fix.