This is the 1/144 RGC-80 GM Cannon.
It's a set of three: an HGUC GM, an old kit, and a Guncannon.
From start to completion, I left it alone for so long that I've lost track of how many years it took.
I don't think leaving it alone until I felt motivated to do it was such a bad thing.
During that time, a wide variety of materials have been released, which has helped me solve problems I was having trouble with or allowed me to come up with new solutions, which has improved the final finish.

1/144 RGC-80 GM Cannon | 八丸's Gunpla works