I built this in August 2017 from the parts in my 1930 No.7 set when I was staying  in Oshawa, Canada with my son and his family. The set has now been re-patriated to the UK. The model is  a Hand Operated Gantry Crane model No.5.31 from the 1931 4a (no.5) instruction manual which is about right for the age of the set. All of the parts used are dark green except the large nickel sprocket wheel. I have always liked the look of this model although have never built it, having the number 1930 7 set has given me a good opportunity to do this. It is a fairly simple but attractive model but would have been a lot easier if a bit more guidance was given on the structure of the gantry. Such as the knowledge that to get the track the correct width requires a compound strip to be made up from a three hole strip and two fishplates at each end of the braced girders. In contrast there is an excellent picture and instructions showing for the construction of the trolley. The instructions are shown on the left. Very few constructional changes were made, adding some additional bracing and stops for the trolley. It looks rather smart all in green particularly the braced girders. I have always thought it was a pity they were not painted green in the post war period to match the other constructional parts. The 1931 instructions show closed end braced girders but most of mine are open ended but some are the closed type in the exact matching green. I imagine there must have been a change over period when parts were changed from nickel to colours, they are not repaints but in the original Meccano green enamel. This type of crane is still very much in use today (usually called a hoist) although often powered by electric motors but in many cases workshops still use chain operated hoists. Picture above taken August 2017 at the Watercress line Ropley railway workshop. Page published August 19 2017 revised July 09 2021
The original instruction page from the No. 5 manual publishedin 1931