So you mean to say these Technics/NAD/Sansui tuners are not that sensitive ? If aging/misalignment is the real problem, auditioning could help. But do you think all the newer Receivers are better in sensitivity/gain/Stability ? but good that you warned about the reliability of such Tuners...
.... I am saying this from my personal bitter experience.
Even if you get a brand new tuner, unless you live within 30 Km radius of the transmitting tower you wont get clear stereo signal. For that you will have to build your own Yagi antenna as you can not get the same in the market.
And Yagi for FM/SW I can think of Folded Dipole/Log Wire but the length of Yagi for such Frequency would attract more authorities than Radio Stations - I have nearly been a HAM and build such Transceivers DIY. Building the best antenna is a hobby in itself and for pleasure of listening I would recommend a Receiver with better gain, because the challenges start with building your own antenna.
All the best for the search pal!