Nice car Richie, I hope you enjoy it. They're certainly rare and guaranteed to become more precious as the years go by.
I'm not a Z1 owner and so don't know and specifics on the cars, but you may want to post the area that you live in to give yourself a better chance of success in locating a specialist? If you're in Aberdeen you don't need a recommendation of someone in Cornwall, or vice versa!
Most BMW's are pretty straight forward, so a local specialist will probably be able to fulfil most of your needs. If they are a true specialist they'll know who to pick up the phone to for any further advice.
This is a link to the BMW Z1. Please check it out and pick their brains for information, but come back to this site for camaraderie and a little fun. You'll be welcomed by the members here both on site and at any events that are going on in your area. They're a friendly bunch. They'll also make a real fuss of you're car if they get the pleasure of seeing it.
Watch out for the leg pull though... they're a mean lot!
http://www.bmwz1.co.uk
Have fun with your car.