I built one of the kit years ago as we have a similar vinegar tank in the Toronto Railway Museum collection.

The kit was a beast to build, but it eventually became a model I am proud of, and your friends build looks equally impressive and I hope they are proud of their build! As said, it is most definitely not an easy kit to complete.

A couple of pictures of mine:
https://flic.kr/p/r7G5jS
https://flic.kr/p/qdbPRF

Cheers,

Stephen Gardiner
Toronto, ON