Heater Vacuum Lines
Hard plastic lines can be "patched" with heat shrink (electrical) tubing.
You'll need about 6 ft of 5/32" vacuum hose, and about 3 ft of 1/4" vacuum hose, for a complete re-do.
If the sales associate can tie his shoes, you shouldn't have any problem with finding the correct items, as most of the times, the vacuum hose is kept in the back room of the store, and sold by the foot.
Therein lies the problem with parts stores. Many of them are not able to attract and hold quality personnel. In my local area, many of the sales associates are marginally qualified in the English language, let alone the mechanics of the products requested. Subsequently, it make take several tries at explaining what the part does, where it's located, what it looks like, etc. before the clerk can even begin to search for the part. Of course, not all the employees are in this situation, but enough so that I am apprehensive about going into certain stores looking for a specific part.
The other part of this rant is that some employees don't seem to have a clue about how a vehicle operates. There are many tutorials online--the ones from "Real Fixes, Real Fast" come to mind--that could provide basic knowledge to employees who could become very valuable, considering how much the mark-up is on auto parts. Less that a year ago, I went into a parts store wanting to buy some fuel line for my mower and the sales associate asked his manager, "What's fuel line?" Simple, simple stuff, and the guy didn't have a clue
Dismounting soapbox...
/rant

By that I mean instead of blaming or criticizing parts stores or their "employees" become better versed in whatever you're working with in order to help yourself.
While I agree with your assertions and having been around long enough to recall when auto parts were sold by those who knew their crap these days I'm so much better armed to help myself in acquiring parts etc. Very rarely do I accept advice offered by someone without any real demonstrable knowledge of whatever I'm dealing with.
Dealing with software we hear the term "work around" and I've been adopting that concept for more than a few years now.
As for these hard plastic vacuum lines its better replacing any damaged sections (or entire runs) with the more flexible and durable typical hose. If you know your sizes order it through Amazon. Look for brands like Gates, Dayco, Goodyear ad infinitum.
HTH









