Fire Alarm Model / Type

Hello I’m a new member here I am interested in sirens fire alarm and elevators as well I am looking to move into the fire alarm portion of it. I’m not sure what model I want to buy I just want to hang it on display in my room I don’t want a full board system I just want the notification applicance I’m not sure what model to pick up and how would I mount it on my wall would I just hang it using nails for display. I’m thinking about
Simplex 2903 light plate but I heard they are rare and expensive. I’m looking on eBay and I see abunch go for $20-30 any information would be helpful thank you so much :upside_down_face: