Two version : a static one and a switch & light option. See below PDF ammeter art.
You will need:

-Rotary switch: [https://www.aliexpress.com/item/32971340082.html?spm=a2g0o.order_list.order_list_main.249.71bf1802Eq2Ml](https://www.aliexpress.com/item/32971340082.html?spm=a2g0o.order_list.order_list_main.249.71bf1802Eq2Ml)

-G4 socket: [https://www.aliexpress.com/item/1005009289306165.html](https://www.aliexpress.com/item/1005009289306165.html)

-G4 led bulb warm white 3W: [https://www.aliexpress.com/item/1005007570785675.html?spm](https://www.aliexpress.com/item/1005007570785675.html?spm)

-A piece of threaded pipe ( to hold the ammeter: example a pipe lamp)

-A thin piece of plastic sheet (the one they use in cheap picture frame)

-4 M3 srews (10mm)

IMPORTANT: If you choose the switch & light option be sure to use opaque filament to prevent light from passing through

See Other steampunk device:

Votmeter:
[https://makerworld.com/en/models/1583011-steampunk-acme-voltmeter#profileId-1666332](https://makerworld.com/en/models/1583011-steampunk-acme-voltmeter#profileId-1666332)

ON-OFF rotary switch:

[https://makerworld.com/en/models/1576673-steampunk-rotary-1-2-pipe-lamp-on-off-switch#profileId-1658858](https://makerworld.com/en/models/1576673-steampunk-rotary-1-2-pipe-lamp-on-off-switch#profileId-1658858)

Toggle switch plate:

[https://makerworld.com/en/models/1673663-vintage-on-off-toggle-switch-plate#profileId-1772349](https://makerworld.com/en/models/1673663-vintage-on-off-toggle-switch-plate#profileId-1772349)