Reverse lookup index/match excel w/ duplicates in array

[Bluebug_Rae]

I need a reverse formula to identify the column headers from sheet2 based on model and OS version on sheet1; if no match found return text “OLDER”. It is important for me to note sheet2 contains duplicate model numbers listed in column A; this is necessary due to the various versions of OS potential installed on hardware.
Sheet1
Model OS Version Approved Version
4331 3.12 ?(return column title from Sheet2)

Sheet2(HWSWSTD)
Model CURRENT FV N-1 FV N-2
4331 15.5 15.3 14.7
4331 3.16 3.12 3.08
My current formula, is not considering the duplicate models in first column on sheet2. How do I fix this?
=IFERROR(INDEX(HWSWSTD[[#Headers],[CURRENT]:[FV N-2]],,MATCH([@[OS Version]],INDEX(HWSWSTD[[#All],[CURRENT]:[FV N-2]],MATCH([@Model],HWSWSTD[[#All],[Model]],0),),0)),"OLDER")

Any assistance would be greatly apricated.
Thank you in advance!

 

[Bluebug_Rae]

I have also tried the following formula, which works on small test scale however when I add in tables and larger data set it doesn't work consistently.

=IFERROR(LOOKUP([@[OS Version]],INDEX(HWSWSTD[[CURRENT]:[FV N-2]],MATCH([@Model],HWSWSTD[Model],0),0),HWSWSTD[[#Headers],[CURRENT]:[FV N-2]]),"OLDER")