All the parts I found appear to be interchangeable. I could not find the board for the 1.33 listed with iFixit but did see the 1.5. We love macs has the board listed as Apple part #922-5890, that part number shows the same for the 867MHz,1 GHz, & 1.33 GHz. The 922-6652 is listed for the 1.5 and I can find nowhere that lists it working in the 1.33. It would be best to wait till tomorrow for Ben Eisenman of iFixit, to answer this. He's the most knowledgeable parts man I know of.