Help about a 77 incendary

[tnor_fr]

Hello,
I am studying a section of an incendiary 77 with a model of buckets from the field.
I have the full bottom model and one containing the incendiary ball.
But on the diagrams, the bucket is apparently closed at the back.
Does anyone have an original model to reproduce it as faithfully as possible?
Thank you.

 

[tnor_fr]

The cutaway of a 77 incendiary is progressing.
I now have small buckets (6 per layer) and large ones (5 per layer) and the full bottom models.
I think I will continue with the little ones.
There are still rings to be made.