List of retired numbers has a link on the front page of
www.scta-bni.orgPage 174 of your rulebook has contact info for Chuck Kalbach.
The rulebook contains much more than rules. There are records, contact info for all persons who deal with the many different functions of the SCTA, and advertiser's contacts for all things LSR, use them first - they support you, you can support them.
Try looking past page 170, you may be surprised.
DW