I think this makes sense. I added two commits:
1. DEP3 header
2. Actually install the *.so file into the binary package
The latter is not the final state. I volunteer to do some d-shlibs
patch tomorrow which also involves creating two binary packages: One
package libampl-netlib-solvers0 and one libampl-netlib-solvers-dev.
But this will not be done today.
Meanwhile you might like to read about multiple binary packages -
also the libsmithwaterman control file will be a nice reading about
this.
Kind regards
Andreas.