BURRELL 4.1/2" valve timing

Good afternoon.

Wonder if you can help please?
We're in the completion stages of our 4.1/2" Burrell Traction Engine [armature home build].
I'm not sure regarding the valve timing.
Following the plans, everything is made and assembled.
The three eccentrics [ 2 x valve and 1 x w/pump] and mounted on the sleeve [which also is the governor pulley] at the angles as per the drawings.
The sleeve is currently held in place by a grub screw, just nipping it to the crank for set up purposes. [once set up, the crank will be drilled to locate the grub screw for a permanent fix].
Watching the video on Facebook -https://www.facebook.com/watch/?v=1550486851679129 , I can replicate the port opening just before the piston reaches TDC at either end of the cylinder in the forward direction. [Reversing lever max' forward]
Moving the lever to the reverse position, and rotating the flywheel backward, things seem to get confusing???
Q. Is there a set position for the eccentrics to be positioned in relation to the crank?
The eccentrics are assembled in the way as viewed from the flywheel side of the engine.
Should the piston be positioned say - TDC toward the front or the rear the eccentrics positioned as per the drawing ?

Appreciate anyone who can help or point me in the right direction.
Thank you.