It's interesting that other Indian mangoes were successfully grafted to Manila. On the same Manila root stock I had grafted Vietnamese Cac, Thai Okrung tong, Maha, LZ, and all survive and grow strong, but I could not get one Alampur out of more than 7 trials.
Simon -- as I tried to say I had tried the graft at different ages, from very juicy young red shoots to green shoots, both for scions and root stock, but all were no good. The Manila root stock is about 6 yrs old and relatively vigor. I tend to think it's the genetic compatibility the issue. I will try on a Kent seedling root stock next, because I can't stand my Alampur bonsai.