Old Lotus 1-2-3 program used many different file types throughout its existence and some are still supported in modern programs, but such support is phasing out with every version. Your best bet for this conversion would be to find the original program somewhere on internet (check sources for old apps), or to use some programs that may still support and open .wki or .123 spreadsheets.
Convert Lotus 1-2-3 version 2 spreadsheet file to Lotus 1-2-3 spreadsheet.
We found 3 software records in the database related to .wki to .123 file format conversion.
Microsoft Windows software - convert wki to 123 on Windows
Old spreadsheet program from IBM
Convert from wki file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned wki to 123. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A spreadsheet software application from Corel
Multiplatform software - convert wki to 123 on any platform
Spreadsheet program from OpenOffice.org productivity suite