ECC40 doesn't have much in the way of rolling options. Most were made by Tungsram. I have some Tungsram totally NOS apart from 3 hours use. PM if interested.
Does your Lampi have any other sockets?
No, most were the skirted kind made by Phillips. Tungsram appears to be better! Send a pair to Lukasz if you can, as I dont think he has heard them. My local guys no longer has any.