RARE German Bundeswehr M35-50 1951 BSG and 30 similar items

This is a rare and unique German Bundeswehr M35-50 helmet. Featuring only vent holes, this variant of the M35 was issued briefly as WWII was winding down and given to western border guards of the BSG for a short period around 1950-1951 before the military transitioned to the solid shell helmet M35-53 and newer models. The helmet is a size 62 as indicated inside the back side. The liner inside is marked as a size 53-57. This helmet has a distinctive liner that is not attached to a ring at the rim but instead is connected to the inside of the helmet dome with prongs meeting at the inside peak under a padded main attachment, and lined with a tanned, 8-flap leather lining secured with a boot-string-like cord. I was unable to remove the liner to check for the manufacturer of this particular helmet, but there is no other marker on any exposed areas inside the shell, so I do not know which supplier made it for the officers of the border guard. While I was trying to figure this out, I noticed a name written several times inside. This particular name bothered me the whole time, worrying that I might be on the wrong track trying to solve this mystery. Eventually, it all started to make sense when I quickly discovered that Spanish volunteers had fought alongside Germany during WWII. The name written inside this helmet reads: Rafael Almanzar Martinezy. Not a German name, but now it all became clear. This helmet belonged to a Spanish volunteer, one of the wearers of the M35-50 helmet: the Bundesgrenzschutz (BGS / ?Federal Border Guard?), which was the first national-level armed service established in West Germany after WWII. Established on 16 March 1951 as a subordinate agency of the Federal Ministry of the Interior, the BGS initially focused on protecting West German borders. During their early days, BGS units had military structures, training, and equipment. The law enforcement officers legally held military combatant status until 1994. A significant number of early BGS personnel joined the newly founded German Armed Forces (Bundeswehr) in 1956, contributing significantly to West Germany?s rearmament. The BGS was renamed Bundespolizei on 1 July 2005. Therefore, this helmet is very rare and special as it belonged to a Spanish volunteer. I am certain that an experienced war historian would be able to provide more insights and correct any mistakes in my research. One more thing to note about this helmet is that there is another marking on the leather liner. In larger marker it reads: 332 C.M. I wonder what this means? In any case, this helmet would be a valuable addition to any militaria collection looking to include a named Spanish Guard Volunteer in their ensemble. Please see all photos. I included a few of the border guard and how this type of helmet appeared within their ranks and uniforms. Contact me to ask any questions, provide any additional info or make me an offer! Thank you!