Dont need to pull out a valve offcourse(really stupid to suggest such a thing), its a T S/N so its from 1985. Its still basically an upgraded 2204, and no it does not have the 'bleed' flaw the 2210 design had in the earlier version. The filtering and power supply structure was changed in '86 i think, the 2205 design was changed after the 2210.
Anyway, this one sounds pretty good to me, would like to have other tubes then the EL34's in it some time, still this one is still stock which makes me hesitate to alter it. For what its worth i dont believe anything written about these marshalls, i have heard better tones coming from a JCM900 HG dual rev after a point to point mod(i think it was called that), so nothing lost. If you have a later 2210 with a cheaper OT(main difference IMO) and such, just replace them with a better one, small cost, big tone!