Hi can anyone enlighten me on the trevor james flutes, what numbers and letters mean the type of model, series or anything else

You are in the UK, right? You should go directly to the website of the Trevor James company itself: www.trevorjames.com

Take a look a the different flute offerings, their model numbers, and descriptions. Then contact (or go the the website of) some major flute dealers and look for the same information, with prices.

You'll soon learn all you need to learn. If you STILL have specific questions, it would be best to contact the staff at Trevor James or the UK flute dealers.