Is it alright?

[sturmmann]

Is it alright to attach 1937 year breast eagle to 1943 Wehrmacht tunic?

[Lustmolch]

Well, it all depends, really. The factories would continue to use old stocks of earlier insignia until they ran out, so it is possible that older insignia might appear on later pattern tunics. The thing to do is check your references. Wade Krawcyzk's book on German uniforms has a Gebeirgsjager M1942 tunic with early insignia on it.

[Craig]

IMO, you can get away with just about anything as long as it's not too weird. The Germans were still issuing a lot of pre war gear right up the last year of the war. Take a look at as many pictures of German POW's as you can lay your hands on and you will see every manner of tunic, helmet, hat, pants, boots and insignia. This is the main reason why I shake my head at most reenactment units who state you must wear this or that. They are kidding themselves and even though their unit turn outs in immaculate identical uniforms look good, for the most part, especially late war, it is not representative of what units looked like at the time.