Metadata.txt ? - Some application are not published sinced years (e.g. MPDroid, Book Catalogue)

I try to understand the metadata.txt file to write a shell script for maintaining updates.
I’m a little bit confused if I misunderstand the documentation https://f-droid.org/docs/Build_Metadata_Reference or for some application (see below) the build software is since several years not published to the repository.

MPDroid

I have taken a look at https://gitlab.com/fdroid/fdroiddata/blob/master/metadata/com.namelessdev.mpdroid.txt

There is:

Current Version:1.07.2 Final
Current Version Code:54

According to https://f-droid.org/docs/Build_Metadata_Reference/#Current-Version
1.07.2 Final should be the freshest version.
So I tried to fetch: https://f-droid.org/repo/com.namelessdev.mpdroid_54.apk - but it isn’t available :frowning:

I compare this now with: https://f-droid.org/packages/com.namelessdev.mpdroid/
Here I see that the Version1.0 with Version Code 20 is advertised (from 2012)

What is the missing point here ?

Book Catalogue

Another look I have taken was: https://gitlab.com/fdroid/fdroiddata/blob/master/metadata/com.eleybourn.bookcatalogue.txt

Here I see:

Current Version:5.1.1
Current Version Code:168

According to the Build entries I understand that this version build is disabled.
So my next Idea was to read reverse the build entries till I found the first not-disabled entry.
This would be here the Version 5.0.7 (Version Code: 151).

As above for MPDroid I can’t either download the Version Code 151 (or 168) :frowning:

So I check again https://f-droid.org/packages/com.eleybourn.bookcatalogue/
Here I see that the Version 3.8.1 (Version Code 70) from 2011 is the last available version.