The two guns were fairly similar in overall size and configuration but I can think of five differences which might show up at 1/76 scale.
1. The gun shield on the 7.7cm was flat with a foldable upper section - the backrests for the axle tree seats are on the foldable section. The 75mm does not have a folding
section with the top of the shield curved back.
2. The 75mm had a prominent "snout" over the barrel attached to the gun shield - the 7.7cm did not have this.
3. The front of the receiver was different between the two guns - the 7.7cm had a flat triangular part the 75mm had a prominent "acorn" shaped fairing.
4. The top of the breech was flat on the 7.7cm with the breech actuating lever attached to an axle on the top of the breech. The 75mm had a couple of different breeches -
the early one used a screw actuator with a noticeable side extension of the top of the breech housing the screw - the breech lever was attached to the end of the screw. The later
75mm guns (M1909) used the same breech as the 7.7cm.
5. The safety frame for the gunner was different between the guns - the 7.7cm was a loop, the 75mm was a simple bar.
I'll pull out some images (forum software seems to have limits - FK 96 n.A images first) .....
Yes, the splinter shield variations are the most readible indentification features. I might add other cosmetic differences existed; most notably barrel lengths. The FK96 was 82 inches from muzzle to breach base, while all the subsequent models measured 89 inches.
Many thanks to both of you for your generous help. Some of the features have been sitting under my nose without me noticing them for ages, so thank you for teaching me how to see.
Another detail question, if I may. I understand all these guns had seats fitted to the front side of the shield. They are missing in many museum pieces, and details are very hard to make out on period pictures, so is there any hard and fast rule how they looked on the 75mm guns, esp. on the Italian M06?
The 75mm Krupp gun was supplied in both foot artillery (no axle tree seats) and field artillery (axle tree seats) forms. The field artillery gun was slightly lighter than the foot artillery
type. The ordering countries determined the proportions of each type supplied - for example the Rumanian orders of a total 736 guns were almost all the foot artillery type, only about 12
seem to have been the field artillery type.
The 75mm Krupp gun is a topic of considerable complexity - it's not surprising there hasn't been a definitive text on these. Perhaps we should try to organise a collaborative project on
these guns - I doubt whether a single researcher would have the resources to track down all the variants of these guns. The Krupp guns not only were supplied in different forms but
they were also modified in the 20s and 30s in various ways to increase the max. elevation of the gun. The 75mm gun was in service for a long time - it was in active service in Israel's
