Vintage WW2 1940 retailer A.M. Capt. Field’s Improved Boxwood & Brass Parallel Map Ruler

Hi, i am selling some of my odd items that I have collected over the years. Here for sale is a Vintage WW2 1940 Air Ministry Capt. Field's Improved Boxwood & Brass Parallel Map Ruler with A.M. and crown markings and dated 1940. Overall good condition with some slight cosmetic markings. Please see photos for condition and sizing as these form part of my description. What you see is what you get. One of many items for sale on my eBay site. I have given as much information as I can, anyone with any further info on this item will be well received. Thank you in advance. A great COLLECTABLE item. If you require any more pictures etc, please ask. International postage costs are for outside of Europe. Please enquire for costs to Europe and any available difference will be refunded. All items can be collected if required.