Useful External Stamp Collecting Links
(let me know if you have any other useful links I can add)

• The Missing Imprimatur Project
  A website where you can view examples of the Great Britain Queen Victoria line-engraved missing imprimatur stamps.
• ImageSleuth - free tool for revealing postmarks
  Download page for ImageSleuth, a free tool you can download to your PC to help in identifying indistinct postmarks on stamps.
• Great Britain and Ireland postmark finder tool
  A very useful tool that allows you to enter a partial postmark in order to find out what the full postmark might be.
• Great Britain Philatelic Society
  Probably the world's leading society and website for detailed information about Great Britain stamps, including images of the imprimatur sheets.
• YouTube Great Britain Philatelic Society Videos
  Highly informative YouTube videos related to collecting Great Britain stamps.
• Telegraph Stamps and Cancels of Great Britain
  A site providing information about telegraph stamps and cancellations.
• Revenue Stamps of Great Britain by Eric Jackson
  A site providing information about the revenue stamps (fiscals) of Great Britain.
• StampBoards
  A forum for stamp collectors to discuss anything stamp related - somewhere you can ask others for advice.
• Maltese Cross forum
  A thread on Stampboards where you can ask for advice on Maltese Cross postmarks.
• 1841 Red-Brown Imperforate plating forum
  A thread on Stampboards where you can ask for help plating Great Britain Queen Victoria line-engraved 1841 1d red-brown imperforate stamps.
• GB QV 1d Red 1854-1864 'Stars' perforated stamps forum
  A thread on Stampboards where you can learn about or ask questions related to the 'Stars' stamps - a huge area of collecting possibilities.
• 1840 Penny Black plating forum
  A thread on Stampboards where you can ask for help plating Great Britain Queen Victoria line-engraved 1840 penny black stamps.