With little experience and age on your side, I would be prepared to describe why you were interested in pursuing a CPL/IR - what interests you particularly in a career in aviation? How much do you understand about the industry and which path do you think your career may take within the company? An 86% average pass mark and a couple of retakes is nothing - put any perceived negativities behind you and approach every interview as an opportunity to promote what you have achieved; I know several line pilots flying for UK operators who did not achieve a pass in the first series at CPL or IR Skill Test and frankly, I'd be surprised if you were even asked.
Remember that everyone invited for interview is likely to be at a very similar level to yourself (i.e. freshly minted CPL/IR/MCC) so it's what the rest don't have but you do that will make the difference - personality, presentability, passion (well, some interest at the very least)...and know something about the aircraft you have experience of currently - it's not expected that you will have a deep technical understanding of the type(s) operated by your prospective employer (do know what they fly though), but few candidates seem to recall much about PA28's or Seneca's or whatever device they used for MCC and this is quite revealing. The interviewer is unlikely to know that much either but that's not why you are being asked
. Make sure you prepare some meaningful questions based on some research about the company - don't inspect your shoes and mumble when asked if you have any...
And if you can pole dance, all the better - just ensure they can provide the facility during the interview.
Overall, a prospective employer during interview is more concerned with your conviction for working for them and how much effort you have put into preparing for the biggest day of your career so far...soft skills appear to be lacking these days so invest in some proper interview prep and improve your chances.
Good Luck