New to Lugers - What is this Script ?

[SQRL]

THis pistol has very few markings. There is this ornate mark on the top. What is it? There is a serial number on the frame, beneath the barrel -- ABCD (four numbers) followed underneath by what appears to be a lower case "a" .

A few other parts have the same last numbers, i.e., "CD".

That's all I can find !
(The magazine has a slightly different 4-digit number and some other marks. I assume it is not the original.)

With so little info, how do I ID this pistol?

Thanks for any help or direction...

~Charly