My awesome secretarial....where does it come from?

I love love love this piece and have had it with me for over 35 years. It was antique when I got it, and now I am the antique. Other than it is my most prized possesion, I honestly don't know anything about it. I've kept it in awesome condition but it really has no information that I can find to be able to identify it. No nails were used, only dowels, and the glass is very thin and dainty. The door is a drop down desk and it appears that it was used. The metal lock states it was "Made in England." If you have seen anything like it, or can identify the marking in the back, I would love to hear from you!

Thank you.