Arvin Model 81 field coil problem

[cameronflyer]

Help,
I've been working on this Arvin this weekend and ran into a surprise that is totally my fault. I checked the transformer and coils and finding no real trouble I proceeded to replace most of the pertinent caps. As i was preparing to power her up for the first time I realized I hadn't checked the speaker. Here is where the surprise hit me. The field coil is blown open. I removed the coil and disassembled it only to find that the wire that carries from the inside of the coil to the outside was burned in two and it took out most of the other windings in the process. To say I was disappointed is an understatement ! It burned right through the tape that was supposed to insulate it. The riders list the field coil resistance at 900ohm and .2ohm on the voice coil. The speaker is 10 inches in diameter.
If anyone out there has a solution to my problem IE spare speaker or workaround for the field coil I would really appreciate it. Thanks in advance for any help.
John