Mixing Unattended MSO 2003 & 2O10 installs

[lurk&jerk]

I have created unattended install packages for MSO 2003 Word and Outlook (because I prefer those versions over their counterparts in MSO 2010) and for Office 2010, from which I install Excel, PowerPoint and Publisher and instruct setup "do not remove previous" office versions. But if  I execute the automated 2010 install after 2003 I get the infamous "mapi32.dll corrupted" error when I try to launch Outlook 2003 and neither reinstalling or repairing Outlook 2003 or any of the online fixes floating around on the Internet work in restoring Outlook 2003 functionality.  In addition, Outlook version 2010 has a shortcut in my start menu even though I instructed OCT not to install Outlook 2010.

If I install  MSO 2010 manually, I don't have this issue.

Is there a way to create an unattended 2010 install that won't overwrite Outlook 2003 (and again, I selected the option "do not remove previous versions" in the 2010 unattended setup).

Edited August 11, 2018 by lurk&jerk

[jumper]

Perhaps the 2010 install updates mapi32.dll to a version that doesn't work with 2003. If so, place a copy of the old mapi32.dll in a .local folder with the Outllook 2003 executable:
<path>\<Outlook2003>.exe
<path>\<Outlook2003>.exe.local\mapi32.dll

Edited August 13, 2018 by jumper

[lurk&jerk]

@jumper, yes, I've tried that. It doesn't work. Even after un-registering and re-registering the .dll. I think Microsoft is so insistent that users upgrade Outlook 2003 and Word 2003, that the only way to install higher versions of office without over-writing Outlook 2003 is to do it manually. Oh well... 

Edited August 14, 2018 by lurk&jerk