The open molded hole is important if you are picky, or it the tracks had a prominent end pin. I have had really bad luck with Friul tracks, as 6 out of 10 sets I bought had left-left or right-right sided links. I ended up punching bolts and washers to cover all of the holes for 3 of the 6 (IS-3, Cromwell, Churchill), which was very tedious! The other 3 are sitting around waiting for a day when I feel like doing them.
On a related note, I just got in some metal tracks by Sector 35 via Hobby Terra:
http://hobbyterra.com/search.php?subcategories_id=92&manufacturers_id=64
They look like Friul tracks, but come pre-assembled! There are a couple of loose tracks plus some wire for you to finish up, maybe to account for varying tension. They cost about the same as Friul sets, but the tedious pinning of the track segments is done for you. The two sets I bought (IS-3M and KV-I/II) are both correctly handed.
https://flic.kr/p/C1CWcc][/url]Sector 35-KV-II-01 by N.T. Izumi, on Flickr
https://flic.kr/p/B4dXjZ][/url]Sector 35-KV-II-02 by N.T. Izumi, on Flickr
Oh, and a test fit to Trumpeter's KV-II sprocket reveals perfect match of width and tooth pitch. I also tested the IS-3M set to the sprockets onTrumpeter's Object 704, and they fit as well.