I got a nice 6-tube nixie clock as a gift.  I have it at minimum brightness, which seems to suggest they will last a long time.

However, being that only NOS is available, I would like to buy a replacement set.

Any dealers you suggest that would be able to give me quality, tested goods?  If I am not mistaken, the IN-14 is generally soldered internally, so not possible to swap them to test.

Thanks!