Even though I’m not from around the area (pure Teessider to be exact), you could try WH Malcolm at their Grangemouth yard and railhead (about half an hour’s drive up the M80 and M876 from where you live). It’s mostly 45’ boxes for Tesco’s, etc, that are often lifted on and off the trains there. We often collect rubber compound for export in stillages from there. Canny lads and lasses there, so it’s well worth a try.
There’s also Jardine Transport at Johnstonebridge. Come off the A74(M) at junction 16 (for Annadale Water services) and then follow the B7076 for a couple of miles or so south until you get to Lockerbie Truck Stop on your left. As soon as you turn in there, take a sharp left (like you are coming back on yourself) and then their yard will be on the left hand side. They do general haulage and pallet multidrop. We often deliver cattle feed there from Holland.
There’s Hayton Coulthard/Eardley International at Ecclefechan.