Did u try importing the ALSB jar file directly in OSB 10.3.6 ? Try and see if it works. If tried let us know what issues you get.For ALSB 2.6 you will have to raise and SR with oracle.
BEA Archived products are no longer available from archive downloads. Please refer to the below notes in support site.
BEA Release Archive (Doc ID 763603.1)
Requesting Physical Shipment or Download URL for Software Media (Doc ID 1071023.1)
The second document has details on how to request for installer of archived BEA products. You will need to raise an SR following the instructions mentioned in the second note.