George,
The oil throwers are probably just large thin washers that fit on the main journals to fling oil away from the main bearings (to prevent excessive leakage). If there was no oil in the bottom of the crankcase, you may find the joint faces have become distorted, in which case, you will need to file/scrape them back to get a good joint. Only use a thin paper gasket, don't be tempted to use a thick gasket - that will only cause more distortion. Also, some of these late 20's machines had a drive side main bearing that was 21mm wide or 2 bearings 10mm wide with a 1mm spacer between them. The 21mm wide bearing is no longer available, but you can use a 20mm wide main bearing from a postwar machine, with the 1mm spacer fitted into the bearing housing first.
Hope this is of some help,
Regards,
Eddie.