If you haven't already done so, get a subscription to EPC and put in your VIN -- it will be fairly helpful in giving you _mostly_ correct part numbers. The problem with EPC is that it doesn't tell you what is still available. And it is at first rather confusing to use. But it is wonderful for finding parts, and then cross-referencing the parts to see what other cars they were common to.
I have the CD which I tried to use once and found to be rather useless, the 250 SL parts book that doesn't have the MB parts numbers, the big 250 SL dealer parts book that DOES have the numbers, and both Big Blue Books. Start with EPC and the CD and acquire the rest of the docs as they appear on eBay. You might check with Benz55 on eBay.