How to best combine/map values from separate inputs?

I’m trying to produce output containing Value and Item ID from separate files.

I have two input files for this, with different naming for the fields For example,
Transaction Name=TRANSACTION
First Name=FNAME
LastName=LNAME

In addition, one file contains the id, the other contains the value. I need to combine these into an output with Instance (text value) and the ID value. I have a gate setup to create a doc with input0 and input1 as shown below.

Input0
“Instance”:“Transaction Name”
“ID”:“bae77”

Input1
“TRANSACTION”:“AC00014623”

What I want this to look like is:

{TextValue":“AC00014623”
“Item”:{“id”:“bae77”}

I have about 40 of these pairs, slightly different in each file.

Any recommendations or ideas?