Acreage held by 1943 lease

We’ve been approached with an offer to lease some acreage in East Texas. However, the oil company determined that this acreage is being held by an old unit several miles away.

The acreage in question was originally part of a 1943 lease conveying acreage in 20 other surveys.
The acreage they want to lease is not contiguous to the unit and separate by other surveys also not in the unit.

How likely is it that the operator will release this acreage back to us so that we can lease it to this new company? And is there any legal remedy we can seek if they don’t?

Unless you have a Pugh clause to release the acreage, the old lease may hold everything.