Q: Will this reverse mandrel work with the hilmor compact bender that I have? It's about 3 months old but would like the reverse bend option
Yes, the Hilmor 1890999 Bending Mandrel will work with your Hilmor Compact Bender Kit 1839032.
Q: Need the full bender set with reverse, when it will be available ?
The full kit with bending attachment can be found at this link here: https://www.trutechtools.com/1926598