Fake Germany Occupation Covers (Lithuania/Serbia/Ukraine) + German Field Post

I recently purchased a large collection of Germany occupation covers. Several are high value if genuine. Do these photos reveal any obvious signs that the covers are fake?

German Occupation Lithuania (Mi 1-8 and Mi 10)



German Occupation Serbia (Mi 16-25)



German Occupation Ukraine (Mi 8-11, Mi 17-20, Mi 25-28)





German Field Post Crete (Mi 7a) — although this was previously authenticated by DrDub (see bottom right corner), I believe his expertising marks were forged.

To be honest, the pictures aren't large enough or clear enough to ascertain much of anything.

The pics are too small really for close up examination of these philatelic covers.

Let's try that again…

The Feldpost cover looks like the Inselpost stamp (already canceled) was placed over the top of the stampless covers already existing cancel.
If you look carefully at the end of FELDPOST in the cancel on the stamp you can see a glimpse of the T under the stamp,very close to the S.
The eagle is very thin which is a real give away also because it was overlaped to form a circle.
So IMO :manipulated cover-so FORGERY
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The lower left feldpost cancel I think reads 27973.A list of the units concerned.As there is no date on the cover impossible to know from which unit it originated.The date could be under the stamp?
Tunis would be very nice!
27973
(Mobilmachung-1.1.1940) Stab I Infanterie-Regiment 86
(2.1.1940-27.4.1940) Stab I Schutzen-Regiment 86
(15.2.1942-30.7.1942) Stab I Panzergrenadier-Regiment 86
(10.2.1943-23.8.1943) gestrichen (Tunis)
(6.4.1944-9.11.1944) 5.5.1944 Feldlazarett 684
(6.4.1944-9.11.1944) 19.8.1944 Feldlazarett 684 u.
Truppen-Entgiftungs-Zug II/133.

I see no reason to think that the Russian stamps cover is fake. Similar items have been sold at Cherrystone in the $170-200 range.

I appreciate your responses perf12 and rogdcam.
The stamp on the field post is slightly pulled away from the cover (right side), but I don't see any markings underneath except the top of a T, as you noted (what a sharp eye).