Recently had GCIV recovered along with rails. I got the table used from a very good friend who suddenly passed away. I took the table apart and reassembled the frame only. Leveled it dead nuts. I'm a professional carpenter with 40 years in the business. I paid to have slates leveled, cloth installed and table reassembled. Mechanic screwed slates down and used the leveling bolts only no shims. He used two paper spacers at each slate seam and liquid glue when he got them "leveled" no seam filler at all. I have some very bad rolls across one seam and a ball can settle into the other one. Sort of like a small gutter. Is this normal practice to not fill seams? If not, what would be the best material to use?