Question 1

Can anybody post a picture (or a link) of the periscope/periscopes in use in the soviet ISU-152/122 as I've got open hatches on my Dragon version so need to scratch some

or I guess a decent sized pic on the Tamiya part, as I see they are in their kit, but none of the sprue images I've seen on the web are large enough, or well lit enough to make out the detail

and on a related note

Question 2

Were the periscopes fitted permenantly (they don't seem to fold away, and stick out a fair way and could get damaged by crew climing in and out)?

or were they removed and stowed when driving in the 'hatch open' state and only fitted when at risk of combat

Wartime ISU-152 had MK-4 periscopes in roof hatches (in 3 hatches in total - 2 round and 1 square) - click image to enlarge:

http://ru.wikipedia.org/w/index.php?title=%D0%A4%D0%B0%D0%B9%D0%BB:Gundlach_periscope.jpg&filetimestamp=20100702175829

The driver has vision hatch, which consisted of armour plate with vision slot and bullet-proof glass.

Post-war versions ISU-152K (1956) and ISU-152M (1959) had periscopes of another types.

As for question 2 - I don't know, how it worked on wartime machines, but ISU-152K/M had the periscopes, that could turn in a horizontal plane, and they could bend in a vertical plane. After the periscope has been inclined, it was fixed by special screw.

Great, just what I needed thanks

now I just have to build it

MK-4 drawing from original ISU-152 manual: