HELP! What tweeter will work in HTA?

[JKent]

I need to replace the tweeter in a "High Tech Aspirin". It is 4" diameter, truncated so it is 4" by 3-1/4"

It can only be 1-1/2" deep because that is the depth of the cabinet. Metal dome is approx 1" diameter.

Label reads:

HTA by Cizek

#ACO 01TO1C 6 ohm

made in Norway 31/91

Just had the woofer refoamed by Bill LeGall at Millerspeak (great work) but he can't fix the tweet.

Thanks for any advice

Kent

Update: For those who may be faced with this problem in the future, here's how I solved it: Bill at Millersound suggested they may be SEAS. I emailed SEAS—both US and Norway. Norway replied immediately with helpful information (US not so much). They told me this:

SEAS made a tweeter for HTA. The tweeter was called H0581-06 25TAC/CDW-HTA. We think this is the tweeter you are referring to. The parts involved are unfortunately no longer available. To find a similar tweeter available today, please look at H1147-06 27TBC/G:

http://www.seas.no/index.php?option=com_content&task=view&id=83&Itemid=1

That tweeter is sold by Madisound but it is $45. But Mad also sells the SEAS H9932 replacement voice coil for the H1147, and that is only $18. I emailed SEAS again to ask if that would work and got this reply:

The rep. set should fit, since the top plate diameter and the radius for the screws are the same. But I assume the two different tweeters are using different screws. If you use the screws from the old tweeter, they might be too long. If you decide to test this, please be aware of this.
The front plates are of course also different, but I figured out that you noticed that from the picture of the 27TBC/G.
Since my problem was a fried VC I ordered the replacement. The screws were too long and had to be replaced but I had some on hand that worked, and one side of the faceplate had to be truncated. Problem solved!