1) Concantanate all of the relavant information for each line item (part number, price, etc.) for list 1.
2) Concantanate all of the relavant information for each line item (part number, price, etc.) for list 2.
3) Put list 1 in column 1.
4) Put list 2 in column 2.
5) In column 3, write formula to compare the item in column 1 row x, with all of column 2. Use the Match function (make sure to use the optional parameter at the end)
6) Copy the formula for the entire length of column 1.
7) Repeat 5 & 6 in column 4, but compare column 2 row x, with all of column 1.
If needed, I can post a working version of this spreadsheet.