There is a Certification of Live Birth from a 1930 birth on the 'net showing 13 digits, specifically 151 1930-010259.
There is also a redacted 1963 Certificate of Live Birth, but the file number is redacted on that one.
Perhaps they just changed the format of the CLB, which is computer generated. Especially the change from 61 to 1961, which could be a Y2K change. The leading zero in the 1961 BC you have seen could have been a result of birth before the sequence number got to 10000 and the new CLB format is designed for number 100000 or greater which might be required at some point.
The copy of a Certificate of Live Birth that I have in my possession was created in July 1962. The typed data on my reference document is clearly made by a typewriter from that time period. There are also five signatures on the document including my own in a data box for a parent. The signatures include the Director of Health for the State of Hawaii, an MD and the Registrar General for the State of Hawaii along with a state seal as well as the delivering doctor. The document’s identification number is labeled as File No. 151 etc. The document is 5 3/8 inches wide and 6 inches long. It is not computer generated. It shows the birth location - a hospital and the usual address for the mother. The COLB from 1930 you reference clearly was not created in 1930. Laser printers attached to computers for generating the type font shown in the 1930 birth document you have referenced, titled as a Certification of Live Birth, were very hard to find in that year on this planet. Clearly this document was made on or after November 2001, per the info at the bottom of the page. The actual location of the birth place is not documented in this extract of Patrica Decosta birth data. This document is only a partial record of birth information and would not be accepted for any real US government security screenings and many other purposes. The Hawaii officials involved with the BHO document, which they claim to have in their possession in Hawaii, most especial the Governor, are not living up to their sworn oaths of office to protect and defend the United States Constitution.
btt — really good find!