You are possibly thinking of the searchable UK patent databases (accessible
through http://www.patent.gov.uk) these contain the majority of the British,
European & World patents inc. those for cycling related equipment
downloadable in pdf format. These relate to the patent No.'s that are often
found on some (but not all) Brooks saddles - really dependant on age. Some
of these can be used to help date the saddle. In answer to a previous
question regarding a saddle that had the old logo and a number '6826/49' on
the cantle plate is replied (see Chuck I do read the archives :-) ;
> The Brooks logo and the patent application No. indicate that it was made
> between 1949 & 1951 !
> This patent (No.6826) was applied for March 12, 1949 (/49) and was published
> in full in 1951. Additionally the oval Brooks logo was discontinued in 1955.
> In this instance the year stamp which I think first appeared from the mid to
> late 1950's won't be much help.
> (the patent relates to electric hot rivetting the of the frame rods (saddle
> rails) to the back or cantle plate).
This was a particularly tricky question, as the number on the Saddle was the Application Number and not the final patent No. as recorded on the patent database and given to Brooks once there application was successfull.
There probably is no single way of easily dating Brooks saddles outwith the years that the two digit year/letter stamp was used, such was the myriad of production changes made over time. Anyone trying to put a +/- 2 or 3 years date on a saddlle without the date stamp, needs to look at (a) the style & cut of the cover (b) the type & wording of the embossed logo on the cover (c) any stampings on the underside of the cantle plate (d) any stamp on the underside of the cover (e) The type / arrangement of the tensioner and (e) The method of joining the saddle rails to the cantle plate.
I would add that though the 'new' logo appeared in late 54 early 55, many saddle continued for some time to be produced with the oval logo.
Maybe a dating article is a good opener for the French & British list. One component the French did love.....