I recently serviced this Eterna Super Kontiki calibre 1489K from the early 1960's for a ClockSavant customer. This is a fantastic tool watch with a great history. Used for a purpose, they typically exude a great deal of character. There was a good deal of discussion with the owner about changing the crystal. While it may appear to be a sin to not change it given the beautiful dial, in-person I can attest that the wabi sabi of this watch, with its original aged crystal, is its own form of art and beauty. Eterna movements were finished to a higher level and nicely executed. Youo may notice that the 1489K resembles an ETA movement-- Eterna contributed to the development of ETA. The calibre has an interesting date change mechanism. You pull the crown to quickset the date. The watch came to me with a broken balance staff. Replacing a balance staff well requires time, quality tools, and skill. Doing it poorly, which is the norm, can be done quickly and cheaply. Making fast work of your watch, perhaps you get your watch back in 2 weeks and at a price you like, the botch leaves it wobbling and limping even if you think all is well. Damage the roller table by hammering it out without care (I typically twist them off, far better when possible)-- no problem for the botch. Your roller table is now bent. Put back your hairspring and bend it? Hell, for 2 weeks and that price, what did you expect? Position the hairspring in the optimum poised position? No time for that, slap that baby back on. Verify the balance is true and in-poise afterwards? No time, I'll put it on my vintage 1960's timegrapher and close my eyes. Take the time, invest in the skills and tools, and do the job well, and this watch now runs with near zero beat error across all positions with an average accuracy of +7 seconds and great amplitude.