4, all somewhat related,
http://www.marlowcasinochips.com/links/davidspragg/borland/borlandfantasy.htm
http://www.marlowcasinochips.com/links/davidspragg/borland/borlandhotstamp.htm
http://www.marlowcasinochips.com/links/davidspragg/osborne/osborne.htm
http://www.marlowcasinochips.com/links/davidspragg/borland/bjmolds.htm

The people responsible for creating these chips had a major influence in our hobby. Bill Borland was probably the single biggest major influence the hobby has ever had.
All the chips referred to were made after the casino's closed so there was no intention to defraud by the makers, and certainly no reason to destroy anything.
Many collectors seek the 'counterfeits' merely because the originals are too expensive to aquire.