I have assembled a guide to the historical manufacturers & retailers of hunting horns as a reference for dating quality antique horns. Any additional information would be gratefully recieved. I hope that this page will make a useful resource and I will add to it as often as I can. Pictures of most of these makers stamps can be found at my website at   http://www.tackagain.co.uk//mall/infopageviewer.cfm/tackagain/Hornmakers 

1] Keith, Prowse & Co 
Keith, Prowse and Co operated from 48, Cheapside , London in the  1800's

2]G.B.Butler 
George Butler started up in Dublin in 1826, then opened a London branch in 1858.Marked "Butler Haymarket London and Dublin".The Haymarket address puts it between 1865 and 1898. 

3]Boosey & Co 
In the 1850 Boosey & Co started making brass and wind instruments and merged with Hawkes & Son in 1930 .

Henry Distin 
Boosey & Co bought out Henry Distin of 31 Cranbourne St , Leicester Square in 1868 so any Boosey horns bearing the Distin trademark would be later than that date

Boosey & Hawkes Ltd 
Boosey & Co merged with Hawkes & Son in 1930 so horns made after this date were stamped Boosey & Hawkes

4]Swaine & Co 
James Swaine started in business in 1798 and moved to 185 Piccadilly in 1835 .Swaine & Co dates horns to before 1845 when James took his nephew into the business and the company became Swaine & Adeney

SWAINE & ADENEY  
SWAINE & ADENEY 185 PICCADILLY LONDON PROPRIETORS OF KOHLER & SON MADE IN ENGLAND. Horns made after 1851 usually bear the exhibition medals from that year.

Swaine & Adeney merged with Brigg's in 1943
 

5] Kohler & Sons
 
Kohler & Sons 12 Gt Chapel Sreet. Westminster (From Covent Garden) London .The mouth piece is marked K & S. Kohler horns carried various addresses over the years which helps to date their horns quite accurately.

Kohler & Sons 
Kohler/Kohler & Sons were manufacturers of horns from 1780 until 1907 .

The company achieved Royal Appointment in 1801 They were registerd at various addresses over the years one of the earliest being I.Kohler - Whitcomb Street London 1790-1793

35 Henrietta Street 
Horns made between 1830 - 1863 usually carried the 35 Henrietta Street address and after 1851-62 the Exhibition medals

12 Great Chapel Street , Westminster 
Horns made between 1863 & 1881 carried the 12 Great Chapel Street , Westminster address.The Kohler inscription became Kohler & Son in 1863.

116 Victoria Street ,Westminster 
Horns made between 1882 & 1888 were marked with the 116 Victoria Street , Westminster address . From 1888 to 1896 the address changed to 61 Victoria Street

167 Edbury Street ,Eaton Square 
The address between 1902 & 1904 was 167 Edbury Street , Eaton Square , London

185 Piccadilly , Covent Garden 
From 1905 until 1907 the address was 185 Piccadilly , and in 1907 the company was aquired by Swaine & Adeney
 

6]Henry Keat & Sons
 
Henry Keat have made horns for all the leading saddlers including - Merry , Whippy , Wilkinson & Kidd , Cornish & Rogers as well as Army Navy Stores and Potters of London .

When Swaine & Adeney took over the business of Kohler & Sons in 1907 Keat & Sons made all their Hunting Horns till 1984.
 

7]Rudall Rose & Carte 
Rudall Rose & Carte operated from various addresses in the mid to late 1800's.

From 1852 to 1857 they were at 100 New Bond Street , London.

From 1858 till 1878 they resided at 20 Charring Cross , London.

And from 1878 onwards the address was 23 Berners Street , Oxford Street , London

8]Louis Jullien 
Louis Jullien sold horns from his music shop in Regent Street which he operated from the mid 1840's until he went bankrupt in 1848

I am happy to be advised if any of the above is incorrect and will modify the information accordingly.