Search our properties to buy or rent. Properties available in Alexandria, Dumbarton and Cumbernauld. If you are thinking about selling or letting your property contact us today for a FREE property valuation. With over 30 years experience in sales and lettings GPM Estate Agents have the industry knowledge to help you sell or let your property. Not only are we experts in property sales and lettings, but we are residents within West Dunbartonshire and so have direct knowledge of local areas including Balloch, Alexandria, Renton, Dumbarton, Loch Lomondside, Old Kilpatrick, Bowling and now Cumbernauld.