OK, now the fun begins :-)
You should also compare your (presumably customised) 12.5 htmpl file with the out-of-box 12.5 version of the same file - these will most likely be at <12.5 install folder>\bopcfg\www\htmpl\web\analyst.
For each of the differences that you see between the 12.5 original and 12.5 customised file, you need to decide what was the purpose of the change in the 12.5 form. For example, was a field moved, added, hidden, or re-labelled? Then open the 12.9 form in Web Screen Painter (WSP). I recommend using WSP rather than notepad, as for one thing WSP will place your modified form in the correct site\mods folder and will not let you edit the original in bopcfg! Find each element in the 12.9 form that matches one that was changed in the 12.5 form - click on a field, for example, in the 'Design' view and you can then switch to the 'Source' view to see what the internal definition of the field is - and repeat the change in the 12.9 form. Save, Publish, test, back up the contents of site\mods so you can recover if things go horribly wrong - and repeat...