>>6328910No idea t b h but probably a quick google search in some to some place like armorama maybe have something. If it helps Vallejo has resisted like a champ in my living room without yellowing in the sunny coast of Spain so I'm quite happy with it, ammo mig I can't say as it's been there only 3 months.
>>6329189I'm not sure they have a name, in the lab a lot of measurement equipment has them so it's not a rare item. I found it searching "extension spring" in pic related (traction spring would be more technical and a direct translation but I'm not sure). Also they have it back in stock fyi.