Hey Andrew hows it goin. Dont have an A-5 but there is a section in the tech area where there is a link to a site that has manuals for various markers. go to the linked site and download your manual, it should have a list of the o-rings you need. Hope this helps man. If it doesn't try googling a-5 manuals you may be able to find one there. Have a great one man and best of luck selling you tuner man!

Also when you get the sizes you need check out high-tech seals on about 92st and 41 ave (check address) they will have all the o-rings you need at a very reasonable price. If you find out whether their imperial or metric you can pick up a kit that should have most of the sizes you need and you can fill the rest in piecemeal from their stock.