Neutron,
An AMO 56" bow is still 4" shorter than an AMO 60" bow. They won't be "about the same tip to tip" as you thought.
Many bowyers make a shorter bow, many are similar to the Bear Kodiak Magnum or Super Magnums. Even the other bow manufacturers (Pearson, Browning, etc.) of the time made similar short bows, or bush bows, meant for use in heavy brush, blinds, or treestands.
You might want to save some money and get an old Bear to see if it fits your needs. Then if you want you can go to a custom bowyer for the grip you like and pretty woods if you like that sort of thing.
Bear made the following short bows:
Kodiak Takedown with a wood or metal A-riser and #1 limbs is AMO 56"
Bear Grizzly is AMO 58"
Kodiak Magnum is AMO 52"
SuperMag is AMO 48"