Help with ID of B-17

[sospri]

We have a piece of a B-17 that we found on the old Rougham airfield site. It's not a huge piece but there are these various numbers stamped on it, so we're trying to ID which plane it may have come from. We've looked at the serial numbers of B-17s stationed at Rougham, but can't find anything that matches these numbers, so hoping someone might be able to point us in the right direction of where to start with these. Some of the numbers are a little hard to work out but I think they are:
2220 604 (also has 157 stamped on)
709
70 2280 7081

 

[cvairwerks]

With what you have, there is no way to determine a specific aircraft that it came from. The best you could do is determine which builder it came from, and maybe the production block. The 157 stamp is most likely a heat treatment inspection stamp. 2220604 would be a part number stamp. A quick run though what I have access to, doesn't indicate that either part number belongs to B-17 production.

 

[Wurger]

The inspection stamps look like the Douglas factory. Boeing didn't use the shape of the marks IIRC.

 

[EAIAnalog]

Boeing likes to stamp parts with their drawing numbers. In the first image, you can make out 2220 and 604. In the second image, it looks like 9 2220 70??. There is an engineering drawing, 69-2220, which has a part labelled 604. Drawing title is Cradle Installation for Extra Fuel Tank, which appears to be located in the bomb bay. The drawing applies to the B-17E/F.