Trident 660 temperature voltmeter addon

I am using this voltmeter / thermomether
https://it.aliexpress.com/item/1005002289526408.html
I custom-made the cap and a new glass with a sheet of clear perspex.
I then used a black foil to make it dark .
Another option could be to use the original cap and glass in this case you have to mod a little the 3d printed base I uploaded a step version just in case.