Crap! Just realized I put the sprocket shaft 180 deg out on the 1,2,3 arm - the oil pick up cup is wrong. Back to the garage...
This is why it is important to take lots of photos. Here is the engine during disassembly showing the correct orientation of the cut outs / oil catch cups on the chain tensioner sprocket arms. The catch cups have to face up to feed oil to the sprocket bearings. I initially put the sprocket shaft in with catch cup facing down which would have lead to oil starvation and early sprocket bearing failure on the 1,2,3 side - a real bummer.
Again, original 1,2,3 sprocket support arm with catch cup facing down/right:
After correction, 1,2,3 sprocket support arm with catch cup facing down/right:
If I wasn't documenting my work with this forum thread, there is a good chance I would have missed this error. Just dodged a bullet....