Yes, you can add LNBs to that dish with some success (see my signature for some of the ones I get on 80cm and smaller dishes). You should be able to get 97W without much problem. It is possible that you might not get all the transponders (depending on your location in its footprint) but, for example, I do get all the transponders on 97W on my 75e elliptical with an LNB 6 degrees off centre. Of course, your mileage may vary.
You need to make/acquire a bracket to attach the LNB to (search on multiple LNBs on the forum will bring up some examples of brackets, as well as pointing instructions).
To aim it correctly, looking at the dish from the front, an LNB for 97W will be to the right hand side. As well, if 97W is higher in the sky at your location than 91W, then it goes lower than the LNB at 91W, lower in the sky, then higher (it's all backwards). There will be a gap between the outer edges of the two LNBs of around an inch or so, but you will be able to tell by moving it in small increments.
Due to the size of the dish, 6 degrees off centre will fit comfortably. You could try for 95W (and on the other side for 87W) but the LNBs would have to be crammed against each other, which probably would reduce signal, and may be to unusable levels.
It is all experimentation, and your results may vary from mine, but even if, for example, you only get most of the transponders on 97W, at least you have something extra to watch. Good luck!