Great find--it should be a shooter! As best I can tell, it's a 60" AMO. Not sure about Howatt, but a lot of the older bows "bucked" AMO rules on string length--the AMO string length is 57" for a 60" bow, but many of the older ones went 4" shorter. Dacron only for the string, 56.5" flemish (to give you more adjustment), 12-14 strands,should work fine.

Chad