Volvo Repair: 88 740GLE Auto rear axle problem, rear axle assembly, volvo 740gle

Question
Dear sir,
I need help with my car's rear end problem. I just busted by rear axle because of driving it with the leaking rear end. now I need a set of used rear end assembly to replace it. But the problem is that this model has so many rear end configurations. Also, I couldn't get any help from the dealer. They just simply did not want anything to do with it.

So far the shop that I brought my car in narrowed it down to 3 possible models- type 1030, 1031, and 1041. My questions are:

1. Could you possibly specify me exactly what model my car is using.
2. I had been trying to find this thing for three weeks already, and it is still hopeless. So if you could suggest me some online place or a place I can contact for this rear end assembly, that will be greatly appleciated.

Note:
Car Info:
1988 Volvo 740GLE B230F Auto
Vin# YV1FX8843J1270583
- The mechanic told me by counting the gear teeth, that the gear ratio should be 4:10 nonlocking, since the information tag was pealed off. But when I looked at Haynes manual, it only shows that my 740 shold have one of these 4 ratios- 3.31, 3.54, 3.73, or 3.91:1.
- Just of your information in case you happend to know the part shop near by, I live in Austin, TX.

Thank you very much in advance. This place has been great to me and I really appreciate your help.  

Answer
Hello,
      I assume you plan on replacing the complete rear axle assembly.
         It really dosen't make a big difference which rear axle assy you use as long as it's from a 740 that had a auto. trans...I think.
          Don't get into changing ring and pinions...the set up procedures require EXACT settings...if you screw up the rear axle assy will either fail or make noises.

          While you're at it...clean up the emergency brake assy....clean and lube moving parts...you'll be glad you did....later

  Bilbo