What you say is a logical assumption. It's just that the Waterford and other Paramount websites indcate that the sequence number was only two digits. This implies that less than 99 framesets were typically manufactured in a month. A jump to at least 262 is a BIG Christmas rush. If there were months where over 100 were prodiced you would think that the websites would indicate that the sequence number was "two or three digits'.

However, your point does have merit. Prior to 1970, the serial number format was MYxx, where M is month indicator, Y is year indicator and xx is sequence number. In 1970, the fomat was changed to MYYxx, reportedly because of "added capacity for the boom years". Normally, I would associate added capacity with more frames being manufactured, but in the this case the sequence number is still two digits and does not allow for any increase! One would assume that an increase in capacity would have necessitated a three digit sequence number, but the only change to the serial number is to add a digit to the year indicator, so that the decade is included. Hmm, all these websites would appear to be wrong, or at least incomplete. The boom and added capacity should have necessitated a sequence number of up to three digits, unless pre-1970 production had been very small, like 30 frames a month. If a two digit sequence number is correct, then the change in fomat was not to accomodate increased capacity, but to add decade resolution.