Landships II

Here are the photos of the tank with the silver interior. 

https://m.warhistoryonline.com/war-articles/know-russia-two-mark-v-tanks.html/2

I also refeared to these picture.
In my opinion these tank were sand blasted before starting refurbishment and this is correct if you want a long durable restoration and most of all repair all cracked plate.
I such old vehicle cracks are caused by the thermal surface treatment to improve protection after that you obtain a plate with different strenght from the outer surface to the inner. This cause lot of tension on the metal and after long time a crack may start from the weakest point. When the crack starts it is usually impossible to stop until it reachs the other side of the plate. A good way to stop cracks is to drill a hole on the end and then fill hole and crack with electric welding.
To do this a sand blasted surface is the optimum because you can easier find the end of the crack. Not doing this, the crack will restart on the other side of the hole. It is a long time consuming work and not an easy task so you need lot of patience and a skilled welder.

I think page 7 and 8 picture were taken after sand blasting but before starting repairing work, see how many broken plates were. See on page 8 what seems a remain of the old green paint on the bootom plate of sponson. These tanks had really bad broken armour plate and I think most of the demage was cause either by some WWII demage and by the change of temperature between russian winter and summer season. In this condition sand blasting is really an hard work because, due the heavy plate demage, you can't disassembling the tank.

Look in this video how to demount a female sponson

https://www.youtube.com/embed/E3WeDtoyyOw

Note in pages 10 (interior horn) and 13 what seems to be remain of the older interior paint. It appears to be white or at least a creamish paint but this last color may be a result of decades of wheatering or even a wromg color balance on the camera.