Some podcasts on iPod not showing on iTunes

Hi,

I have an old (gen 5?) iPod nano, which I upload music and podcasts to using iTunes on Windows 10. Recently, I tried to clear out the long list of old podcasts from the display in iTunes and pressed 'delete from playlist', which accidentally removed all podcasts on my device from view on iTunes (the 'On this device' bit). But there were still about 8 podcast episodes on the device. These can still be seen and played on the iPod, but do not show up when I connect to iTunes on the PC, so I cannot delete them. This means I have about 100-150Mb of storage lost whilst I can't remove these.

Can you help me figure out how to delete just these episodes from my Ipod, without having to wipe it and re-upload 15Gb of music and podcasts?

Thanks