Can prior service wear awards from their previous branch on their Army service uniform? What literature would have the answer?

Only awards received while in the army.

One cannot transfer from one branch of service to another and wear the branch awards from dat previous service branch

AR 600-8-22

The answer is usually yes, but it depends. For example, I can wear my Army medals on my Navy uniform, but not all of the ribbon only awards. Also, Army marksmanship badges and Air Assault wings cannot be worn on Navy uniform. Check the regs for details on which awards and other insignia can/cannot be worn on the uniform of your service. Regardless, all awards should be in your service jacket.

Yes but not all of them. Check AR/DA Pam 670-1. If you cannot find what you are looking for there, check the HRC website.

Yes. Check 670-1. Order of precedence applies.

Absolutely. I'm not sure what the Army version of the "awards and decs" department is called but I would start by submitting your prior service DD214 to them to get your ribbon rack built with old and new decorations. You earned them, wear them.
I am prior Navy now in the AF; still wearing submariner's fish and NAMs and others.

Try AR 670-1

there are rules preventing you from wearing some national guard and army reserve ribbons while on active duty, but if you got something in the air force, navy, etc, you should be able to wear it.

DA PAM 670-1 will tell you everything you need to know on the matter. But short answer, mostly yes.

Depending on the award, ribbons and medals most likely, but badges ie efmb, jump wings, surface warfare, etc, highly unlikely