I was messing around with Guncho myself a little while ago, so I know a little bit, but not much!
Guncho uses an older version of Inform than the current one, (version 5T18) so make sure that you’re using the reference docs for that version.
The Guncho help wiki seems to be permanently down, but I’ve put up a new realm on Guncho, called “Guncho helpworld” with all of the wiki contents I could find.
I’ve left the code for that realm public so that other people can not only read the source code, (so they don’t have to use a MUD client to get the info) but (hopefully) amend and extend it as they discover things I got wrong or want to add new material.
Don’t be put off by the large number of errors you’re getting at the moment: don’t forget that with any compiler the first time it hits something it doesn’t understand it throws the compiling process out of whack and often reports perfectly good code following the error as being problematic.
As for your code, I can only suggest using an incremental approach.
Put in only the things that use the most basic aspects of I7 (like rooms and their connections, say, that are the least likely to change between library versions) and see if that compiles. Then slowly add the more demanding/esoteric/modern code.
Good luck!