IERC tube shields

[PharmRock]

I wasn't able to make it to the local HAM fest a few weeks ago to scrounge up some of these, so now looking to get some of these on e-bay.  I see the T6-1020 and the T6-6020 both are appropriate for 9-pin 12A_7 types, they just have different construction as to how they contact the glass envelope. 
Are either of these "better" than the other?  I am considering them mainly for EF86 vibration dampening as suggested by Sluckey in a different thread.

Do the IERC shields work with the traditional base used on the 9-pin Belton socket with shield? https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=TubeSockets&ORDER_ID=581341771
or do they require their own socket/base?

I already have my sockets mounted and wired in the chassis, so if the IERC shields won't work with these, I'll probably forego getting them.

Finally, are there IERC shields available for EL84's?  If so, what is the model number?
 I suspect it would be T6-10XX or T6-60XX (I've read the last 2 digits is the height of the shield in inches (e.g. 20 = 2.0"), so maybe XX=25 or 30 for an EL84?).  Seems like a shield that would function to dissipate the heat would prolong (theoretically, at least) tube life.  Which is becoming more important these days then ever considering supply issues. 

Thanks for any info you can share.

[sluckey]

All of mine are TR6-6020B and work well with the Belton sockets.

I would not bother with EL84s.