Restoration
If someone is restoring a vintage aircraft to its original does anyone know what sort of criteria are used when deciding what level to restore it to? I am thinking mainly of safety criteria.
The sort of thing I am wondering about is suppose I found a Mk1 Shytalk rusting gently away in a barn and decided to restore it. I then find that when the Mk1 was originally introduced it was found that there was a design fault which meant that, occasionally, the left wing fell off on take-off. A modification was introduced to correct this, with the modified aircraft becoming the Mk2. In this case, obviously, restoration would include the mod (so there would be no chance of a Mk1 ever being restored). However if the difference between the Mk1 and the Mk2 was a different design of ashtray there would be no need for the mod and I could happily restore my Mk1.
Somewhere between the two must the point where mods must be applied but is there an official definition? I would imagine that if the mod was directly for safety (gluing the wing on better) it would be a must but would something which, for example, lowered pilot fatigue (and was therefore an indirect safety aid) be mandatory?.