We all get radios that need them. What happened to the originals? Likely someone is squirreling them away thinking they will be gold someday.
Well, free material to make them abounds. Just grab an old PTV set and remove the fiberboard back section. I have made several nice backs by making a cardboard template and using a coping or jig saw, cut the board into the correct shape, drilling it for mounting holes- AND ventilation holes.
I have even wound look antennas and hot glued or epoxied them to the new back.
Don't forget to mark the make & model # of the set on the back, if it has a label on the inside, and a tube position and number chart, INCLUDING the pilot light number! Some of the PTV backs have vent holes already also, and that makes it so easy and neat too. Once in a while you can score one of the old console Xistor stereos for hauling it off. (The good ones- wink, wink- nudge, nudge; are Sound Design, Readers Digest, etc.) The fiberboard backs from them are great and the radio becomes junkbox material.
Sometimes an old set will respond well to adding a ferrite loop antenna also, if the original loop is missing or damaged.
A note on grounding:
Use at least an 8' rod. 10'-12' is better if you can find them. the 4' solid and 4' sectional rods from some sources are a joke, don't work worth a hoot, and DO NOT meet the NEC. (Hear that satellite & cable installers?)
Decades ago most publications suggested using a water pipe or the finger stop on the telephone dial (Remember rotary phones? --Geez- now I feel really old); for grounding, if you couldn't drive in a ground rod.
Now most plumbing is plastic. Not the greatest material to use as a ground.
Most old radios do play and receive much better with a good ground.
Remember you CAN make a tuned ground, by making an antenna tuner and placing it in the ground circuit.
Sounds nuts? Well, I read about it several score years back, in a early 1900's magazine or book.
It stuck in my mind as downright odd, to say the least.
Well, another ham buddy that lived in the industrial area of Tacoma WA had so much noise he was almost unable to hear any stations, or talk to them.
I suggested the tuned ground, and he experimented with several types of HB tuners. He found one that worked the best, and that killed about 85+% of the noise!!!
We also added a plastic pipe 2' down around his ground rod and dumped in a couple of lbs. of copper sulphate, and watered it well every few days.) The plants around it LOVED the copper sulphate and grew much better. Note: Some plants don't like it, and it can harm them. (Salt can be used also, but its likely to make the plants die.) That also reduced the noise level.
A piece of wire stuck in a flower pot is NOT a ground either...
Most old radios DO need an external antenna, and ground to work their best. 30-50' is good enough for most sets. Remember a long wire antenna IS directional. I found making a "V" out of it works well as does running an insulated wire up a tree, vertically.