Thanks for reaching out Mark!
I’m sorry to admit this, but I unfortunately don’t fully understand your issue – can you help clarify what you mean when you say this:
I’ve entered a “Please contact us” link in the the message editor of the “Venues” dashboard, but this link doesn’t show up when I associate this venue with an event.
It sounds like what you mean is that you add a “Please contact us link” in your “venue description” field, as shown in this screenshot:

And then, when you create an event and select this above venue as the venue for that event, you want that “Please contact us” link to appear in the venue information but it does not, as shown in this screenshot:

Is this an accurate summation of your issues? If not, what things are different about your actual issues? Let me know in detail and share screenshots of your own if possible (you can just upload them to Imgur.com and share links to them).
I apologize for responding to your questions with questions of my own, but just want to be 100% certain of what your issues are so I can best help you resolve them 🙂
Thank you!
George