Hmmm, an Airstream? For a Monty? Hmmmmm... I guess it's okay, at least it's an RV...
I found this site where you can make a customized mug. I actually created a mug with a picture and the textual saying and it will cost about $16.00 (plus tax and shipping?)for the mug size but stopped short of ordering it. So this will probably work for you:
It might take some looking to find the link I used, but look for custom, then select mugs. There are many types and sizes of mugs to pick from. Then upload a picture and select your text. I think that is a very good price for a one time custom mug built to YOUR desire.
I don't work for them nor do I have any experience with them other than I found their website. I hope this works out for you!