Suitable download of Lion to create a bootable USB?

No, you won't easily be able to make a bootable installer from that download since the installer app must be extracted from the .pkg file. The .pkg file is actually an excutable file meant to extract the real installer to the Applications folder (it actually has to piece together the real installer app from multiple pieces). Unfortunately this .pkg file will only run on a Mac which is compatible with macOS 10.7 Lion.

If this Mini ever had macOS 10.12+ installed at some point, then try booting into Internet Recovery Mode using Command + Option + R. You should either be able to access the most recent online macOS installer available for this model, or it will access the Lion online installer. Depending on the online OS installer being accessed, you may need to change the system date to 2017, or perhaps earlier or later depending on the OS due to the installer possibly having an expired certificate. I know this is the case for Lion, but may also be the case for the online macOS 10.13 High Sierra installer now as well.

Unfortunately the A1347 designation is too broad as it covers models from 2010 to 2012. You can get the exact model by entering the system serial number here:

Check Your Service and Support Coverage - Apple Support

Once we know the exact model, we suggest other options such as a Snow Leopard DVD, or which model Mac you need to find in order to create a bootable macOS USB installer for 10.11 or 10.13, or possibly 10.15.

Hi droptical,

This is what you need to create a bootable installer: Create a bootable installer for macOS.

What you need to create a bootable installer

* USB flash drive or other secondary volume with at least 14GB of available storage, formatted as Mac OS Extended

* Installer for OS X El Capitan or later

Download a macOS installer using the App Store or your browser

To get the full installer, your Mac must be using the latest version of OS X El Capitan, the latest version of macOS Sierra, or any later version of macOS. Download from a Mac that is compatible with the macOS you're downloading. Enterprise administrators: download from Apple, not a locally hosted update server.

If you choose to purchase macOS Lion, keep in mind that the general requirement for are as follows: OS X Lion - Technical Specifications

General requirements

* Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor

* 2GB of memory

* OS X v10.6.6 or later (v10.6.8 recommended)

* 7GB of available space

* Some features require an Apple ID; terms apply.

* Some features require a compatible Internet service provider; fees may apply.

Regards.