One trick is to weld the case shut (you can get a welder on amazon for ~$100). This makes it much harder to open, especially in a non-tamper-evident way. You can open the case back up by using an angle grinder with a cutting disc to slice through the weld.
I'd recommend taking a very high res photo of the welds so you can compare later if tampering is suspected.
Comments
One trick is to weld the case shut (you can get a welder on amazon for ~$100). This makes it much harder to open, especially in a non-tamper-evident way. You can open the case back up by using an angle grinder with a cutting disc to slice through the weld.
I'd recommend taking a very high res photo of the welds so you can compare later if tampering is suspected.