No. 344 Grey Chevron
This pen is from the personal collection of FredRydr - a Montblanc aficionado, and active contributor on FP Geeks and FPN. It is thanks to Fred that I was introduced to these wonderful Spanish Montblancs!
From L to R - Soennecken Rheingold (blue-ray), MB 344 Silver Ray, and Waterman 7 (emerald-ray)
In his book about Spanish Montblancs, Guillén calls the design on this pen a grey 'chevron'. He compares its look to that of the Waterman's Ink Vue because the barrel is translucent and allows the ink level to be seen. Other companies used a similar material and design too, as seen in this picture. The Spanish 32x and 24x models were also available in a blue, green and red chevron.
Interestingly, it seems that sometimes the chevron coloured Spanish pens were covered with plain black celluloid paint. The prices of the black and coloured pens were the same, and so I assume that the Spanish manufacturer had no problem coating coloured pens with black if the latter received more demand and coloured stock was just laying in the warehouse.
Enrique Wiese started the production of MBs in Spain, post-WWII. It is speculated that domestic production was taken up at that time because the Hamburg factory could not meet local and international demand after its bombing in 1944. Also, trade controls mandated by the Spanish dictatorship made it difficult to import pens at that time. Labour and parts were cheaper in Spain, and so MBs would only be affordable in the country if produced there. This makes sense because it seems that Spain's production of MBs stopped once injection moulding technology was introduced in the late 50s and through the 60s. The new technology reduced the need for manual labour considerably and with it the cost of pens too.
This 344 is very close in shape to the German 344 except that the Spanish version has a pointier cap top and of course the German 344 was not made in this colour.
Guillen, J. M. (2014). Montblanc Pens Made in Spain. Guillen.