Coolant leak - dripping from bottom bell housing

Hi Newbe to the forum - have just rebuilt top end of son's 2007 307 1.4 16v following cambelt failure - I have 2 ongoing problems firstly a coolant leak which appears to be dripping out through bottom of bell housing - cannot find any 'obvious' hose leaks - have fitted new thermostat housing which appears dry and cannot see any obvious signs of leakage around outside of new head gasket- does anyone have any idea how coolant can get into bell housing in order to drip from the bottom - my 2nd problem is oil dripping through the newly replaced inlet cam sprocket oil seal and covering the new timing belt etc in engine oil. I made sure all was clean and smooth etc before replacing this oil seal - there does appear to be some minute scratches on the sprocket surface which slides through this seal, but not sure if this would result in such a leak - I only ran the engine after rebuild for a couple of minutes and this was the 'disappointing' result - any ideas or suggestions would be gratefully received - cheers Grant