You appear to have a G&B 96B made around 1940 according to Jack Sim's Gas Pump Bible. The pump looks fairly solid with these models experiencing sever rust issues around the top plate, however yours looks solid. Based on its condition, the pump is a good candidate for restoration and worth the effort, particularly if your doing the work yourself. Missing parts are readily available through the parts suppliers identified on this site. The current trend is to leave the guts inside but I would remove them to save weight and because you have a relatively common pump. There is a lot of knowledge on this site so feel free to ask questions.