I'm not real familiar with the "B" in particular but I know a few tricks from reading about restoring vintage aircraft that have been in storage for decades.
They make a cart that warms and circulates engine oil through a stagnant engine, for about 8 to 12 hours, before they even turn it over. You did that some when you squirted oil in the pistons but the bearings are still dry.
You might drain the oil and replace it with warm oil just before you start the old girl up. Even a light bulb under the oil pan overnight will help. Warm oil gets into the small places faster. If the shaft to the oil pump is accessible, you can turn it over with an electric drill motor and circulate oil without the engine turning. Often, the oil pump is turned by the distributor shaft. Pulling the distributor allows you to see what you have to make to let your drill motor drive the oil pump.
These two things (warm oil and priming the engine by truning the oil pump manually) should get that Allis back in shape like she never set at all.