Yesterday I was looking at the text of how the incense had been prepared. In my ArtScroll book it is written:
בֹּרִיתכַּרְשִׁינָהלָמָההִיאבָֽאָה
A bit later it says:
אַחַתלְשִׁשִּׁיםאוֹלְשִׁבְעִיםשָׁנָההָיְתָהבָאָהשֶׁלשִׁירַֽיִםלַחֲצָאִין
In the first case a penultimate stress is marked with a meteg, while in the latter one the lack of mark indicates a final stress. I checked an Eshkol edition, and it had the same difference. The concordance lists multiple occurrences of both versions too. Shouldn't it be the same?