Is that a Room ID?
How many are you replacing?
If this is a room id, then they are required to be ADA compliant. (Tactile letters and domed braille)
This is a fairly simple sign to replicate...
2 pieces of acrylic, second surface apply the number, backspray the header and footer, VHB the face to the backer (leave it 1/8" - 3/16" into the painted area) the VHB creates a void where the removable message sheet can slide into.