As I said earlier, all the legal heirs are entitled to get their respective shares.
Generally the property acquired through gift / sale deed are to be treated as self acquired property, (if registered) unless specifically mentioned in the deed. (as they pay sale consideration and registration fee)
If you recite particulars of gift / sale deeds of elder sons, in the partition deed, if the elder sons also relinquish their rights, then no problem, (it has to be clearly mentioned in the deed) if not burden of proof lies with you that, the said properties are transfered on to their names in pursuance of partition.
If you failed to do so, they will also ask their share.
Here, you have to understand one thing, in partition one has to register the property to the extent of their share as per partition deed, where as in settlement it is not necessary, but, if you want you can register it.
Good Luck / All the Best