Create deb repository with several versions of the same package
Solution 1:
As far as I understand, mini-dinstall requires debian .changes files when adding packages. As I only had .deb files available I found that aptly supports multiple versions as well.
Another more light-weight option is freight which is a set of shell scripts for maintaining a debian repository. I have now (2017) been using freight for three years to maintain a small but actively updated repository, with good results. One key feature was the ability to keep multiple versions of a package.
Edit: Updated link to new freight repo as the previous had not been updated since 2014.
Solution 2:
The solution is to use mini-dinstall for managin deb repos. It does not delete previous version of the package from the repository.
Solution 3:
I heard good things about an alternative, freight:
https://github.com/rcrowley/freight
HTH, mistige