You made a great trade!!! I much prefer the Howatt's over the Martins. Does it have a Rosewood Riser? If so, Awesome!!
Lets see if I can help with the #'s
9 is the number of the bowyer working at Howatt that actually made your bow. 2 is the last number of the year it was built [ I would guess that would be 1972, [Howatt sold out to Martin not too many years after that] 087 means your bow was the 87th bow of that model made that year.
DO NOT WORRY ABOUT THE AGE !! If the limbs are straight [no twists] put that bow to work!! They are one of, if not the fastest and Most Beautiful of the 'Production Bows" ever built and there were plenty of them before the "mechanical garage door openers" took the lime light.
It has definate value. More than the Martin, I'm sure. So, don't let go cheap if you decide to replace it at some point.
I had all of this explained to me a few years back. As I too, have a few Howatt's in my collection. I'm sure if I'm way off track someone here will correct the info. for you.
Hope that helps, Gene