Classic Radio Cassette and Radio CD from W124 and R107

[Slatin]

Can you help? I have two original Radio Cassettes and one Radioo CD which were removed from my late 80s R107 and eraly 90s W124 and replaced with modern some years back. I have no code for one of them (any takers?0 but codes for other two. How do I test whether they are in working order without re-installing in vehicle? The Radio Cassettes are an MB Audio 10 and a Blaupunkt Verona CR43. The Radio CD is an MB Audio 10 CD. All help gratefully received! Thanks