A useful list of holders can be found on wikipedia and the association also maintains a website.

warrants_1
1. Swaine Adeney Brigg 2. Lock & Co 3. London Badge & Button (Toye) 4. Launer 5. Penhaligon’s 6. Smythson 7. Truefitt & Hill 8. Atkinsons 9. Swaine Adeney Brigg 10. Parker 11. Smythson

(I was surprised to see Parker listed, and it turns out that the company was awarded a royal warrant back in 1962).

warrants_2
1. Ettinger 2. Globe-Trotter 3. Hunter 4. Loake 5. Turnbull & Asser 6. Tricker’s 7. Albert Thurston 8. Kent 9. Jabez Cliff 10. Dents 11. Haws

Images from 2nd.