Best box to ship a used set with a large manual?

[Sauromosis]

I am shipping both a used Passenger Plane (7893) and separately a B-Wing (6208) and need a box large enough to put the manual in flat. 

 

The medium/large flat rate boxes at USPS are no good, because the parts don't weigh enough to justify it, but the many small boxes I have at home aren't wide enough to put the manual in.

 

Any suggestions?  Thanks much.

[c666187]

A Priority Mail #7 box is 12 x 12 x 8, it should meet your requirements.

You can order them free here:

https://store.usps.com/store/browse/uspsProductDetailMultiSkuDropDown.jsp?productId=P_O_BOX7&categoryId=subcatMSS_B_Free

[DoNotInsertIntoMouth]

A Priority Mail #7 box is 12 x 12 x 8, it should meet your requirements.

You can order them free here:

https://store.usps.com/store/browse/uspsProductDetailMultiSkuDropDown.jsp?productId=P_O_BOX7&categoryId=subcatMSS_B_Free

 

That one is the one I use a lot for large sets like that.