Looking for an out of production Czech guitar. Now that's obscure. I've never heard a Marina.
Try this company:
City Music Co Pte Ltd
1, Sophia Rd
#02-12, Peace Centre
Singapore 228149
Phone : (65-) 63377058 ha Fax : (65-) 63385919
You can also try posting at guitarsite.com or some of the other guitar enthusiast sites.
This site has lots of info on vintage Czech guitars and they have a forum that you can post to as well.
Good luck,
ADG Webmaster