An ORRI (Overriding Royalty Interest) is a created interest - in other words, it originates from and is created from a source. That source in your case is an oil and gas lease. An attribute of this ORRI then is that it is only valid so long as, (and only so long as) the source lease is valid. So, from the property description you have on the lease, you’ll have to discover whether or not there was any production ever established, get the name of the well(s), track down the Operator (likely there will have been several over this many years). If in fact there was production and there still is, you can take up a discussion with the current Operator as to your interest and any money that may be in suspense.