lmao....dude, i could have written your post as well !
if the family member is saying the double decker is low tech, i think he is missing the point..... that bus would be a magnet for most anyone to come and check it out, and well...if ya wanna sit up top, ya gotta order lunch :)
it would i think need to be in pristine condition to get the biggest bang for your buck out of it.......
might better check on the beer licence, i have never seen a "moving bar" before, and even then, i think you would be restricted to one county or city limit if set up like it is here....
are you a college town ? if so, i dont think you could loose with the bus.... set it up for good cheap drunk food and pub crawl it till it breaks, lol ! find a nice pretty spot downtown for the weekday lunch crowd, and give them a great unique view no one else in town can.....
if your HD, and town, will let you serve and move, shuttle people across the downtown area back and forth, while feeding them on the run so to say....that one might be pushing it, but its an idea, lol
maybe you could find a second one, just for parts in case you need something, i found one down in georgia basically for scrape weight a little while back.
they are so few and far between here in the states that i really dont think you could go wrong, if just for the "wow, look at that" factor...... and "oohh, its a food bus!!...lets chow" !!
but in the end, only you can decide if they pitfalls would be worth the cool factor it has...