Serial number partially deleted by theft

I have recovered my bike but the serial number is partially deleted. No additional damages of any kind in the bike box. Aluminium Alloy. DH/Freeride bike.
The deletion was made with an angle grinder and the depth don't exceed the depth of the serial number.

What is the thickness of the area in the bike box where the serial number is punched ?

Is a high security risk mount my bike with this defect ?

Have I to substitute the bike box ?

Best Regards