Many pics below
Steve,
The only way to positively ID the 38cm BMW CSL Petri is to check for the part # that is stamped inside the interior base of the alloy hub. The 38cm leather wheel should have the part # of 32 33 1 112 244 and 32 33 1 109 738 for the 40cm foam wheel. Don't know if BMW ever offered the 380mm foam Petri wheels (these may've come from the VW Sciroccos).
The 38cm "244" hub is definitely taller than the 40cm "738" unit. The "244" measures 4 5/8" in height and the "738" hub measures 4 1/8". The corresponding plastic hats/hoods are as follow: "244' cover is 4 1/16" height wise and the "738" is 3 3/4 tall.
As far as the screws used, I prefer the looks of the allen head versus the phillip heads. The allen screws make for a more "industrial machined" look.
All the photos below are from my professionally recovered 38cm BMW Petri bought back in 2007. The 40cm hub is from my leather re-wrapped (over foam core) Petri. I seem to have misplaced this wheel somewhere at the moment and don't have any pics of it.
380mm Petri hub- 32 33 1 112 244. Disregard the extra "1" at the end from both hubs. The stamped numbers are really hard to make out (in particular the 4s) even with a magnifying glass. This is where the camera's macro feature really came in handy. Notice the BMW Roundel logo to the immediate left of the numbers.
400mm Petri hub- 32 33 1 109 738
Wheel with hub and horn button and black ring removed.
Following pics are the backsides of leather spoke grips.
Not very well done here. The stitchings should have been situated exactly in the middle.
Notice the significant height difference between the 2 hubs. Believe this has to do with the spokes of the 38cm being relatively flat vs the concaved spokes of the 40cm wheel. So with the proper hubs installed on both size wheels, they should be about the same height from tip of the splined spindles to the top of steering wheels grips. As deQuincey had previously mentioned, the CSL hub has 4 "waves" vs the 3 "waves of the 40cm Petri.
Hope this helps Steve.
