New user – changing existing posts to podcast posts?

OK… I just installed the plugin, and I have a major question.

The large majority of my site is archived radio shows – I host the mp3s on my own webspace. From here on out I’d like to make future shows added to the site available on Itunes, hence the install of the plugin.

What I’d like to know is if it’s possible to modify the existing posts on my site to have them appear as podcasts for Itunes / become podcast pages for Itunes. All the links for these posts have been shared several times over the years on many different sites, so I’d really like to :

a) avoid having to change existing links to old shows

b) have duplicates.. i.e. the existing old audio post and having to create a new podcast post which both have the same show on it.

Is this possible?

My site is https://www.altrap.com by the way.

Thanks!

https://www.ads-software.com/plugins/seriously-simple-podcasting/