A question for those in the know

[Morris at Heathfield]

Which mills are considered among the top over there?

I believe the "Big Three" are Lochcarron, Strathmore, and House of Edgar. Another well-regarded but smaller mill is D. C. Dalgliesh.

As a matter of interest, is there any other tartan out there called "Ancient"?

The Campbell Clan tartan is sometimes known as "Ancient Campbell", presumably to differentiate it from the "Campbell of Argyll" tartan. Of course, it is also usually worn in ancient colors, presumably to differentiate it from the Black Watch tartan, which may be where the "ancient" part of the name came from.

There is also an "Ancient Forbes" tartan (STA & STWR #212). Despite the name, it is a newer design than the customary Forbes tartan (i.e., the one identical to the Lamont, but with black guard lines next to the white stripe). However, the Ancient Forbes tartan is the one the Clan Chief decided to register with Lord Lyon in 1949. I suppose that makes Ancient Forbes the official tartan of Clan Forbes; nevertheless, the present Clan Chief appears to prefer the customary Forbes tartan.

The Stewart tartan regarded as the Clan tartan is often known as "Ancient Stewart" or "Old Stewart", as there are better-known Stewart tartans that aren't the Clan tartan.

The Ancient Morrison tartan has an interesting history. The Clan Society chose a tartan based on the Mackay in 1909. Then, in 1935, a red-based tartan was found in an old family bible. The Morrisons began wearing this tartan as a Clan tartan, while the other tartan became known as "Green", "Hunting", or "Society" Morrison. In 1968 the (Red) Morrison was registered with Lord Lyon as the Clan tartan; however, the version that was registered had only a single green stripe, which is believed to be an error, but Lord Lyon refused to alter it. The version with two green stripes, believed to be the original version, is therefore known as "Ancient Morrison" (in the tartan registries, at least) to distinguish it from that registered with Lord Lyon.

The symmetrical Buchanan (e.g., "Buchanan #2-4" in the Scottish Register of Tartans) is sometimes referred to as "Ancient Buchanan", although the Celtic Croft prefers "Buchanan (MacGregor Hastie Variant)".

There are plenty more examples. Try searching for "ancient" or "old" on the Scottish Register of Tartans.