Amperex 6DJ8 tube construction

i am not knowledgeable on the fine points of how specific vacuum tubes are constructed, perhaps there or others that can comment who have more knowledge

i would say, having a fairly vast connection of such tubes of various brands/makes from us europe japan etc, 6dj8, 12au7, 12ax7, 6fq7 and so on, that both types of construction you show via the link are quite common... i see more of the ones with the ’intermediate horizontal plate’ leading up to the suspended getter on somewhat later iterations of the various tubes, perhaps it is to make the tube more robust against mechanical shocks and not go microphonic or worse

Left one is Amperex Holland made and a great tube, the one on the right is a Matsushita made on same tooling as Mullard but a different tube.
Always check the etched codes at bottom of tube to identify the origin.

'Made in Holland' is silkscreened on the one on the right. It matches several other ’Made in Holland’ silkscreens on NIB/NOS Amperex 6DJ8 orange globes that I purchased in the original yellow/green boxes, years ago. There are no date/factory etchings on these tubes in the original yellow/green boxes. There are etchings on tubes, similar to the one on the left.

I agree the one with the extra plate may be a ruggedized tube.
Does the left tube have the same Amperex logo? This is a guess, maybe the tube on the right was made in a Mullard plant and branded Amperex Holland. That happened sometimes.