I'm working as a webdeveloper in a firm that has an existing zen-cart store which I have no idea how old is. The first thing i did was to redesign their store and upgrade it to the latest zen-car (at that time 1.3.9h) but after a while I found that the override system is completely f* and the template they use is very difficult to alter the way I want it.

Now I am at a point where i'm torn between whether to do a clean install and start from scratch (using the existing DB), or to just install a new template and customize, or build one myself. The problem however is that the people that have been working on this shop from the beginning are not developers and they have not documented a single step of previous customization, overrides, mod installs etc. so I have really no clue to what they've done in the past.

Anyone been in this situation before? What did you do, or what do you recommend?