B and K - 707 - dynamic mutual conductance tube tester

First my dilemma. How do I rate this thing? It's in perfect working order but looks like $hit. On the outside. The inside is immaculate. There isn't anything wrong with the silkscreening. I bought this 16? 17? 18? years ago. I bought it from an electrical engineer who was restoring these at the time. One of the reasons that these old testers get out of whack is that the doohickey gets dislodged from the thingamajig and causes all of your readings to come out all cattywhompussed. Well, not so with this one, fellow A'goner's. This genius (that's how he referred to himself) came up with a system for the 707 model that practically "guarantees" accurate readings. I included a picture here in this listing so you can see what I'm talking about. See the pic with the bolt in the bottom of the case? Therein lies the genius, friends. This guy used a standard stainless #3 phillips head screw (I forget the length) to basically 'fuse' the doohickey and thingamajig together. THAT'S IT!! No more problems. If you have any questions don't hesitate to ask but also don't get too technical with me. I develop real estate not tube testers. Will ship double boxed.