Pedants, please come and sort out my apostrophes

[mangolassi]

I'm a bit confused about apostrophes to denote possession. Need to talk about an organisation (we'll call it X Y Service) and their work in a particular place (Zz).

1. X Y Service's work in Zz
2. XY Services' work in Zz
3. XY Services work in Zz.
4. Other (please specify)

1 is correct if organisation is called XY Service and the word work is used as a noun (i.e. the work of XY Service)
If the organisation was called XY Services and the word "work" is used as a noun, the correct answer would be 2. (i.e. the work of XY Services)
If the organisation was called XY Services and the word "work" is used as a verb, the correct phrase would be "XY Services works in Zz" as "XY Services" is still singular despite the word Services being a plural.

1. If the organisation was called XY Service and the word "work" is used as a verb, you would then say "XY Service works in Zz".

Does that cover all possibilities and leave the OP totally confused?

Ok, the organisation is Service singular. Work is being used as a noun. So Number 1. Thanks