Fire Truck Decals

There's one generic 1/24 sheet here, about midway down - nice lettering

https://inquarters.com/Fire_Decals.html

Chimneyville Hobbies selling at policecarmodel.com list some silver and gold shaded letters as well as some Maltese crosses and door badges

You may also want to go to the Microscale decals website and check their offerings.   There may be some railroad lettering sets which may be of use.   I've ordered direct from microscale with no issues

Thanks for the input

You can also look at Custom Squads:

http://www.customsquads.com/products.html

Mike