ARC LS2B upgrades? any suggestions?

Does anyone have any experience upgrading an LS2B? Is it worth upgrading or just selling it and take the proceeds and the upgrade money and buy another piece of gear. Perhaps someone knows of simple tube upgrades? Any thoughts appreciated.
I have an LS 2 b
It is a little bright in my system

I have tamed it with a dutch tube a little
but will probably upgrade to an ls5
I have it matched with a D200 solid state amp

Two ways to do it. The cheap way is to change the tube to a good NOS tube. I've tested over 15 different NOS tubes in there, so far my favorite is the Mullard Master Series M10 6DJ8. But it is hard to find. I was lucky to find one. The Amperex 6DJ8 with orange label and a globe logo, white label 7308 are also on top of my list. (This is based on the LS2B MkII I have) The Amperex 6DJ8 orange label is the cheapest.

The other alternative is to upgrade to the LS2B Mk II. I would presume that this will cost over US $1,000. I would not recommend going this route. You can probably sell your LS2B and get an used LS2B Mk II for much cheaper.