I purchased a large second hand Crittall Green house last year and of course upon dismantling to transfer to my home, many of the aluminium bolts and nuts sheared off. I have tried high and low to obtain some replacement bolts and nuts trying other greenhouse and fixing suppliers.The bolts slots into the frame for fixing and securing, they are aluminium slotted pan head 1/2" long by 1/4" dia. The slotted pan head has to be approx 1/8" wide to slot into support channel frame, etc. Many places stock spare greenhouse bolts, but they are the type with square heads, mainly for Halls Type greenhouses. Could anyone tell me or point me in the right direct for a supplier, or perhaps an ex supplier to Crittall in the past? - many thanks in anticipation.