Here are a couple of suggestions for the title covering noncontiguous numbers:
1) How about: Title 10 & 13 (or 10&13)
2) How about ignoring the physical appearance and just saying that you have:
When 11-12 come in, you can compress it all and say you have Title 1-22.
When I worked at Harvard, they were in the process of automating all their
volume holdings. For difficult situations like these, they tried to report
what they had, not what the piece looked like. A note can always be added to
the bib or holdings record to describe peculiarities when important.