Bend up a couple of drawbar guides and fit them to the front chassis crossmember with a minimum 1mm gap between the guide and the outside face of the drawbar section. Fit the guide gussets for a bit of additional strength and tack weld.
Unclamp the drawbar and lift the front end up approx. 5-600mm and check its action. If there is any stiffness or binding, try and find the offending component and adjust or trim/grind as required.
Fit the angle brace centrally over the drawbar face and weld onto the front chassis crossmember only - Do not weld to the drawbar section.
Reclamp the drawbar to the chassis and fully weld.