Hi all,
Reviving this thread because I have a solution that works for me.
I too use manager-accounting and have to switch to windows or run a vm etc. But I just prefer to stay in Solus. The missing dependency for the standalone desktop version is gtk-sharp3. Since there are only a handfull people who currently need it, it is not included in Solus. For those who are not afraid to build their own packages, you can use my package recipe to build this dependency. You can find it https://github.com/ArjenR/solus-gtk-sharp3
Please note that this is only maintained by me and obviously falls outside of the official Solus project. Oh yeah and it is still not very well tested.
To install manager-accounting I extract it manually from the fedora rpm.
Next to do, when I find the time , is to see if the rpm can be converted into an eopkg as well.
Regards, Arjen