Teak Lounge Chair ID?  

I have the same chair. For you, unfortunately the marking is on the seat bottom, which seems to be missing. It is marked Moreddi, which was an importer of danish furniture in long beach, CA. Grete Jalk may have designed some of the pieces and the little brass strip on the seat back is a design future she put into her pieces (like the coffee table and end tables).

How does it disassemble? Does it use keyhole hardware?

I have seen many great chairs that have come from humble danish makers who produced the style / chair of the times.
Even the retched swedish company with the 4 letter name made, and have now relaunched, the 50s range.
http://www.ikea.com/gb/en/catalog/products/10295902/
Sadly not all danish chairs had a great designer bring them to life

Thank you! The chair is definitely Moreddi but I suppose it is unclear who the designer is.

Moreddi was the retailer.
So it is definitely unclear who the maker AND the designer was.