I reckon you've done very well there!
Regarding making the head tilt, I think it's halfway there. My suggestion for what's it worth:
Let the top parts working upwards = table, block, [collet-]body
Remove the block.
Establish how much – or little – you can cut into the flanks of the table and body (or design a new, rectangular-section body – I'll go with the existing for now).
Machine two flat flanks on the body, to which suitable stub pins can be secured as pivots.
A pair of trunnions that screw to the flanks of the table and whose inner faces are a close sliding fit on the body flanks.
Arrange some suitable clamps for the trunnion pins, so the body can be locked into place. Simplest may be to extend them outside of the trunnions, the extensions threaded for locking hand-wheels or levers. Alternatively, make the trunnion-tops be partial-split clamps with locking screws.
The arrangement would be slightly like that on many telescope mountings.