There are a number of place like this that do conversions, I have no experience with this or any other supplier.
https://www.joesclassiccarradio.com/conv.html
I bought a retro sound radio, and it does the job. Shows for a 144 , don’t know why they don’t list the 1800. But they're likely all the same. Check with them directly if you go this route.
https://www.retromanufacturing.com/p...nt=32867768782