Thanks for good scan. I can tell quality on public hairs easily. It gives me full confidence to buy my copy.
If you want JPG files, only DLSite provide them: http://www.dlsite.com/maniax/work/=/product_id/RJ224872.html
If you have Melonbooks readers, I prefer this version: https://www.melonbooks.co.jp/detail/detail.php?product_id=369147
How to get Melonbooks Readers on your Android device: 1. Build a Google account with Japanese language and location (you don't really have to down to real address. but make sure your zip code and city are matching each other). 2. Login your JP Google account. 3. Clear all saved data and cache on Google Play. 4. Restart your Android device. 5. Enter Google Play, try to check your profile. 6. Restart again. 7. Enter Google Play again. you should find your Melonbooks Reader. You can do the same thing on DMM Reader, too.
You can use the same approace to roll back to your original Google account.
What is Melonbooks Readers? And why do you link to the non-Digital site of Melonbooks? I've tried googling but came with no results that explains that, but is it an app that can let you read books from the main Melonbooks online store?
It is a tool for Melonbook DRMs. If you goto their website, you will find that tool, too. However, you must have a JP Google account. If you can't find Doujinshi on melonbooks.com, you may find it in melonbooks.co.jp since .com doesn't use DRM protection.
They have viewers for PC, too. If you have screenshot or screen recording tool, you still can build your own JPEG version.