The 1882 Kelly's Directory lists Fehrenbach & Co, clock & watch makers, South Street, Bishops Stortford, and I would expect similar listings for other years.
The picture shows an 8" dial rosewood mercury wheel barometer, with swan neck pediment, hygrometer, short thermometer, convex mirror and level plate inscribed 'John Fehrenbach of Bishops Stortford'. Replacement finial, tube, main bezel and glass, and setting knob. Original polish in a pleasing brown rosewood colour, showing nice wooden figure traditional to rosewood. Dials resilvered, brass cleaned and lacquered. Circa 1865. Dimensions 9 ¾" x 38". It was recently sold by Barometer World & Museum. Items like this often end up in local museums and you should contact the Bishop's Stortford Museum to see if they have any objects made by the Fehrenbach family.
The Historical Clock and Watch Site has an entry "Fehrenbach, B&L of Bishops Stortford" This may contain little more than a list of trade directory entries giving working dates for this maker but you will need to pay a small fee to access the information to find out.
The British Library Newspaper Catalogue lists the following papers for the period in question: The Bishop Stortford Observer 1861-1862; The Herts and Essex Observer 1862-1979; Bishop Stortford Gazette and General Advertiser for Herts and Essex 1863-1863; East Herts and West Essex News and Bishop's Stortford Advertiser 1889-1899; Bishop Stortford Weekly News and East Herts and West Essex News 1899-1900; The Herts and Essex Journal 1863-1865. Shops selling clocks and watches frequently advertised in local papers, especially before Christmas, and the later adverts may well contain pictures of some of the products sold.
You may find it useful to subscribe to the Rootsweb list UK-WATCHMAKERS-L if you are not already on it.
I suspect you already know that the 1881 census shows that Louis H Fehrenbach (52) lived at the Bridge Beer House, South Street, Bishops Stortford with nephews Joseph (34), John (33) and Andrew (19). All were described as watch & clock makers, were unmarried, and born at Baden, Germany.
Marie Murray has sent the following information which she has collected since the above posting:.
1859 Hertfordshire Directory
Fehrenback, Birthold & Lambert
South Street, Bishop's Stortford
(this is a different spelling) and doesn't tie in with Loomes dates below.
1864 Hertfordshire Directory
Berthold Fehrenbach and Co
(Brian Loomes shows them 1866-1874)
1882 Kellys Directory
Fehrenbachs in South Street.
1884 Louis claims his business established since 1840.
An L.Fehrenbach shown by Loomes in Reading 1854 could this be Louis later moving to B.S.?
Louis H. and Andreas disclaim any connection with John
1908 no Fehrenbachs shown trading in town, except John.
Disc 5 Baden shows no Lucas* (may be Lukas), Berthold, Louis or Hercules searched for with exact spelling.
One should always be careful about "end dates" based on Trade Directories. The publication date would always be after the "survey" date - so someone could have died before the directory was published. The Post Office/Kelly's directories would be surveyed at about 4 year intervals so the dates cannot be more accurate - and some other directories may have pirated old information from earlier directories.. In addition there is sometimes some doubt about the dates associated with some copies - while someone carrying out a search may well not have had access to all publication years - so will not have seen all possible issues. To complicate the matter there would be the occasional omissions and spelling errors ...
Marie Murray reports: Since I last communicated, asking for your help on this subject, I have been fortunate enough, with the kind help of a fellow researcher, to discover where the Fehrenbachs W & C makers of Bishop's Stortford came from, namely St.Margen in Freiburg. Not only that, my friendly researcher has also given me details of a family tree stretching back to the 1700's. Isn't that amazing? After 20 fruitless years of search.
Herts Mercury, 27th April 1889
English fuse 12" dial clock, 8 day mahogany case and key bottom door, B & D Fehrenbach, Bishop's Stortford.
The Late Mr. Andrew Fehrenbach. The death took place on Friday of Mr. Andrew Fehrenbach, watchmaker, of South-street, after an illness (rheumatic fever) lasting only ten days. Mr. Fehrenbach was in his 33rd year. He came to Bishop Stortford in 1879. The funeral took place on Monday in the Roman Catholic burial ground of ST. Edmund's, Old Hall-green, Father Jones, the parish priest, officiating.
Chelmsford Chronicle, 29th November 1895
The Late Mr. John Fehrenbach. The death took place on Sunday at Portland Road of Mr John Fehrenbach, who formerly carried on business as a watchmaker in Potter Street. Mr Fehrenbach was of German nationality, and came to Bishop Stortford in 1869, at the age of 20, to join his brother, the late Joseph Fehrenbach, in the watchmaking business. He married an Englishwoman, and leaves one son, Mr. Max Fehrenbach, who is in the British Army, and three daughters. Mr. Fehrenbach had never been naturalized, and since the outbreak of war had felt his position keenly, his sympathies being entirely with Great Britain. The funeral took place in Thursday following a requiem mass in St. Joseph's Roman Catholic Church, Windhill.
Herts Mercury, 11th AUgust, 1917
If you can add to the information given above tell me.