John,
The Master Parts list shows the following:
1928Q to US-GP725H Part Number 44816 Qty 4 per car.
1929U from US-GP725H to 30U 1558573 With wood wheels as Part# 311781 Qty 4 per car.
(Curious the description says "Wheel Hub Cap (front) (wood wheel) but shows Qty 4 and no alternate part number for a rear wheel before 30U SN: 1558573
After 30U 1558573
Front part number 322824 Qty 2 per car
Rear part number 323830 Qty 2 per car
My guess is that they were all round after US Car GP725H and Canadian Built GP732D up to 30U 1558573 where the Master Parts List shows a different front #322824 and rear 323830
___________________________________________________________
My 29 has on it now 3 round Hub caps without the hex wrench octagon shape. Also I think the octagon shape hubcap came from some 30U wheels that I picked up a year or so ago. (Never noted the cap difference) Since I used one of these hubcaps from the 30U I probably added the hex cap. So this is why I probably have 3 round and one hex.
I hope this and other replies will nail the question down, Chet...
The Master Parts list shows the following:
1928Q to US-GP725H Part Number 44816 Qty 4 per car.
1929U from US-GP725H to 30U 1558573 With wood wheels as Part# 311781 Qty 4 per car.
(Curious the description says "Wheel Hub Cap (front) (wood wheel) but shows Qty 4 and no alternate part number for a rear wheel before 30U SN: 1558573
After 30U 1558573
Front part number 322824 Qty 2 per car
Rear part number 323830 Qty 2 per car
My guess is that they were all round after US Car GP725H and Canadian Built GP732D up to 30U 1558573 where the Master Parts List shows a different front #322824 and rear 323830
___________________________________________________________
My 29 has on it now 3 round Hub caps without the hex wrench octagon shape. Also I think the octagon shape hubcap came from some 30U wheels that I picked up a year or so ago. (Never noted the cap difference) Since I used one of these hubcaps from the 30U I probably added the hex cap. So this is why I probably have 3 round and one hex.
I hope this and other replies will nail the question down, Chet...