Was your wallet.dat file encrypted (was it password protected)?
How old was the bitcoin software you used to generate it? The database it uses changed from one type to another years ago. During 2013 it changed from using Berkeley DB to LevelDB.
When you say the "original bitcoin wallet program" do you mean the first ever bitcoin software released by satoshi?
I have the original bitcoin wallet program, which was version 0.1.0
I tested generating three different wallet.dat files with it, and opening them in a hex editor. The results are below. They all begin with this sequence of bytes "00 00 00 00 01 00 00 00 00 00 00 00 62 31 05 00 09 00 00 00 00 20". If you search your hard drive for that sequence you might locate an old wallet file.
00 00 00 00 01 00 00 00 00 00 00 00 62 31 05 00 09 00 00 00 00 20 00 00 00 09 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00 00 DA 40 08 00 00 00 29 00 A7 04 B9 12 00 00 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 20 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 01 00 00 00 00 00 00 00 62 31 05 00 09 00 00 00 00 20 00 00 00 09 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00 00 D9 40 08 00 00 00 1D 00 BE 0B C7 29 00 00 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 20 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 01 00 00 00 00 00 00 00 62 31 05 00 09 00 00 00 00 20 00 00 00 09 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00 00 D9 40 08 00 00 00 1E 00 29 54 36 19 00 00 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 20 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00