i bought a matched quad to retube my fender era sunn model T. i accidentally broke one tube. (i'm a buffoon). i had to order another set of matched just to replace the one broken one. the problem is that the new set will not match a set i wll make out of the remaining 3 (minus the broken one). so will this be o.k.? and which two tubes work together, and which are the other two that work together, out of the four, once installed? or, how can i identify the (TWO) sets of tubes of the four while installed so i can pair tubes and keep the matched sets together, working together. then bias and balance? does all that make any sense? thanks for any info.