I heard of a guy once in the states who flew a Lear jet non radio. He didn't like them. He just used to phone the fields and let them know he was coming in.
Many fields will let you in non radio if you call them first. Don't expect to get into Birmingham etc, but I imagine Popham , Compton etc will all be pleased to see you.
Flying without a radio, like SSD says is a liberating experience especially from a field like WW. It was the norm in the old days.
You can always buy an ICOM, they work fine and will be useful as a backup for later life if you go onto instrument flying (if only to get the ATIS before you start the clock ticking.)
FFF I don't think the installation of radios needs to be certified, although the equipment does. Lots of PFA aircraft fly on ICOMS. I don't even think you need an engineer to change a radio in a warrrior.