I'm sure you came across some of my old posts, but I owned 3 Mark I Reissues for the better part of 20 years. What I eventually settled on was a 5751 or even a 12AT7 in V1 (to calm the input down a bit), 6V6s in the power section and running cabinets with Vintage 30s. I never cared for the EVM-12L with this amp and liked the Celestion 90 even less. As for EL34s, I liked them better than the 6L6s but not as much as the 6V6s. I think the 6V6s (run in 100 watt and tweed for 40 watts) were the most responsive in the Mark I. It was a vibrant and unique tone. Also, be careful with how you set the tone stack - it's VERY easy to overdo the mids and not get enough treble out of the amp. IIRC, I ran mine plugged into channel 2 with: Vol1: 0, Vol2: 4, Master to taste, Treb: 8, Mids: 3, Bass: 2, Pres: 9 and Rev: 3 with it in 100w and Tweed. The amp was clean and alive like this and I also added a combination of an OCD and an FDII in front for different levels of gain and solo boost.