Alt-Lechhausen

Stage 01:  N48°22.578' E10°55.586' 
Additional question: Nowadays a sign with a big green letter stands in front of the house which you will see on the old photo. Which value (X) in the alphabet (a=1, b=2. . . ) does this letter have?

A =

X =

Stage 02:  N48°22.(A+2)(X-3)0' E10°55.A(X-2)7'
Hint: Viewing direction NW

Stage 03:  N48°22.X1B' E10°55.(A/2)(B-A)7'
Hint: Viewing direction NW

Stage 04:  N48°22.XA0' E10°55.(B*C*3)'
Here you will find even two suitable pictures.

Stage 05:  N48°22.XCA' E10°54.(A+B)(B+D)2'
Hint: Viewing direction SW
Here no more house looks thus as earlier. Nevertheless a vague alikeness is still to be recognised.
For verification: The across sum of A*B*C*D*E should be 18.

Stage 07:  N48°22.(F+1)(F-B)0' E10°54.XF2'
Note: viewing direction N. Here you can only recognize the house on the far left edge of the historical photo.
Additional question: What house number (Y) does this house have today?

G =

Y =

Stage 08:  N48°22.(F*100+7*G+Y)' E10°54.XAX'
Hint: Viewing direction NNW
Note: On your actual location formerly there stood the nice "Gasthaus bayerische Floßlände" which you can see on the historical photo with the figure 8.

Stage 09:  N48°22.(F+H)BC' E10°55.HXF'
Here you can see the parent house of the family Behrbohm which is well-known to all old inhabitants of Lechhausen. Though in the course of the time the house has experienced some rebuildings, it still is identifiable fairly good.
Additional question: How many windows -without cellar windows- (Z) does this house have in its gable wall nowadays? 

I =

Z =

Stage 10:  N48°22.BFC' E10°55.IBX'
 Note: viewing direction NO. The houses on this street don't all look the same anymore.
With a little imagination you can still see a vague resemblance.

Intermediate point:  N48°22.475' E10°55.520'
There is no task here. This intermediate point only serves to prevent you from falling into a dead end.

Final:      N48°22.(K*K*Z+47)' E10°55.(K*90+15)'