Please help me to see if this will is valid. Houses related to leasehold rights.

I think this will is valid. Although the house was leased when the will was made, it was invalid at that time, but after the house was purchased, the will was not amended, so it is still valid now. If there is a will, it shall be inherited according to the will. As for whether the will itself is the expression of the true meaning of the old man, you can ask the judicial organs to identify it. Strictly speaking, when his wife died, the family property should have been inherited once, and the elderly can get general property. The other half will inherit according to the will, and the intestate will inherit according to the law. But there was definitely no inheritance at that time. In any case, if the will is true, then other children have no right to inherit the house.