[Ron Ramirez]

Hello Michal, and welcome!

You can find a 71 schematic here:
http://www.philcoradio.com/tech/images/71.jpg
You can also obtain a complete schematic package from Chuck at the Philco Repair Bench, which includes all available service info for your set. The price is very reasonable.
http://www.philcorepairbench.com/schematics.htm

Yes, a K-7 is the speaker that was used originally in your 71. I see that someone cut the field coil from the original speaker frame and fastened that to the inside of your cabinet.

I suspect this version of the 71 was brought out in either Fall 1932 or January 1933, since it uses a shadowmeter. Model 71 sets did not use shadowmeters at first, but this feature was added to production sets later on. This cabinet was previously unknown to house a 71 chassis. Yet another undocumented Philco.

Thanks for sharing the pictures! Good luck with your set.