V4 Reverb machine

[goltigut]

So i really like the sound of my freshly fixed early V4 (aluminum knob version) and especially the sound it's reverb tank. I use it mainly for recording purposes. Now i'm thinking I could use it as a reverb unit. So i'm thinking about installing a dry signal mute switch so i can put any source through it and recording only the wet reverb signal. What do you think could be the best way to implement such a mod without affecting the cosmetics and the sound quality of the amp ?

http://www.ampegv4.com/images/schematics/V4.jpg

thx