Mine has 908756 block and seems to be right off the shelf, except the 4 valves were removed, hose clamps added to the 4 lifters and bolts put into the valves guides. I thought maybe the bolts were there because somebody switched blocks at some point BUT the bolts match the assembly bolts used on the rest of the setup. I also have a double rear plate to give the starter more support, but I plan to beef that up some more. Mine does not have these nice plugs in the valve holes, so it seems they made changes over time.
Thanks to everyone who is helping find the parts to restore my '42 Script GPW. Still need a good windscreen, rear seat and top bows, David (443-865-4800 / email@example.com