Other than
my resource in the Notes & Resources section (which only covers Section IV questions but for all topics), I am not aware of any free resources covering Operations. Of course, this does not mean that you should not try to search for such resources, both in the Notes & Resources section and elsewhere. Although it is not guaranteed, with a bit of luck, you may end up finding something useful.
However, there are paid resources that sort past exam questions by topic (this applies to all topics). To my knowledge, Five Senses Education offers such resources, consisting of two books, the first one covering Section I and Section II questions, and the second one covering Section III and Section IV questions. If you are willing to spend money on Business Studies resources, then you may wish to consider purchasing these.
Alternatively, a good approach would be to work on gathering as many questions as possible covering all exam sections, not just for Operations, but for all topics, and doing so during the holidays. Not only will you have enough time then, but you will also not be under the pressure of having to complete assessment tasks and sit exams like you would during each term.
I hope this helps!