actually....the widow and others are more copies of the Browning BackPacker than anything else....Harry Drake was big in development of a few Browning recurves most notably the Browning Wasp and Browning Explorer models.
Black Widow, Habu and a few other also use the mass forward setup with limbs rear mounted. It is an efficient and stable setup though heavier than some other designs...but is solid, reliable, steady and makes a great bow.
I also think the Silvertips have the riser mass if you get the Dymonwood riser that is resin impregnated...maybe some older Bruins....
A few others that are similar in feel and function...if not specifically visual appeal.
Good luck...