Lens Assembly Spacer Again!
After some extensive search, I found some M2.5 standoffs. I bought 15mm, 20mm and 25mm. I used the 15mm long ones.
I used the original bolts on top to hold the lens assembly to housing securely. I left the ring on the lens and slid it down so it is blocking any light passing though the gap.
The results speak for themselves:
Perfectly square and stable image. It is not moving or shaking every time I bump the table.
That last one is of the focused projector.