Hi Dirtbeard,
WBCCI #967 was assigned to your parents in the
1962 thru 1998 WBCCI Directories. They were listed in the
1960 Directory, but without a WBCCI membership number. Directories were published at the end of the year thru
1960 and then at the beginning of the year for 1962+, so there was no
1961 Directory. #967 was unassigned in
1959 and has been unassigned since 1999. What this tells us is that your parents joined the club, most likely in very late
1960, which could be appropriate for a
1961 Bambi which began production in late 1960, but they weren't assigned a membership number until 1961. In the early years only members that went on a caravan got numbers, but by the early 1960s numbers were assigned to all members. You parents eventually went on some caravans starting with Airstream Company Caravans to Eastern Canada in 1978 and Mexico in 1979 and eventually continuing with several WBCCI caravans in the years that followed.
Regarding #967, most of the rest of what people have posted is correct. Since about 1970, numbers below 1000 have been reserved for special usages (club officers, etc.) and thus cannot be reassigned to the general membership. Currently the numbers 900-1000 are reserved for future usage, though 899 and below do have defined purposes. There is no way for you to be assigned your parents #967 without this going to a vote of the clubs International Board of Trustees. While not impossible, it would take a compelling case to make this happen. Choosing a number than incorporates 967 would be easier. We have one current member that has 16921 that incorporates the parents number 692 between two 1s. Others have suggested different possibilities. Good luck!