Mullard Experts?

[sparklesmcgraw]

I have the chance to buy a yellow label Mullard ECC83/12ax7 tube with the date code I62.

I am with the understanding these are quite rare as they only made the I62 revision for a short period?

What would be the estimated value for one of these that tests strong?

Sparklesmcgraw

 

[sparklesmcgraw]

On a side note:

Is this the same as a M8137 'box anode' mullard?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180477648831&ssPageName=STRK:MEWAX:IT

 

[Gusfmm]

I'd not say these have any special value over any other I61 or later much more common I63. Mullard short-plates I'd say go on Ebay for $50-$100... depending on their use/testing values/box etc.