Drummond ran into serious financial trouble, and was in default to its bank. It went through a reorganization (the terms of which I do not know) and came out the other end as Excel. I do not know what former shareholders of Drummond received in Excel - that is the mystery here, and will effect what you ultimately end up with, if anything.
Excel was acquired in 1995 by Ranchmen's - .3 share of Ranchmen's for each Excel share. Ranchmen's was acquired later that year by Crestar - $2.81 cash AND .225 share of Crestar OR $6.125 cash for each Ranchmen's share. In 2000, Crestar was acquired by Gulf Canada - 3.333 shares of Gulf AND $3.25 cash per Crestar share. Gulf was acquired in 2001 by Conoco for $12.40 cash for each Gulf Share.
Conoco is now ConocoPhillips.