5 x 7 is the speaker dimension, not a part number.

I bought and installed my speakers in 2004, so the part numbers I used are likely obsolete. 5 1/4" round or 5 x 7 oval will fit this location, you need to find the absolute shallowest speaker you can, preferably with a non-paper cone. If you google Blaupunkt overdrive you will still find hits with technical specifications, if you can find a speaker under 2" in depth it should clear all moving parts.