Randall often used a three thick and two thin spacer arrangement on non-leather handles during the seven spacer era on smaller knives made from 3/16" stock. It can be difficult to some degree to "date" some of these as they can go either way, from late 60's to mid 70's.

By say 1977-78, RMK went to a thick center spacer arrangement on both leather and non-leather that lasted to around 1984 when the switch was made to all thin spacers.