I have spica angelus speakers, how do I know when the cross over needs rebuilding?

Just did a quick search and came across this Spica enthusiast site,  it gives you all the info that you'd ever need. 

http://spicaspeakers.com/specifications/spica-angelus-datasheet.php

Thanks everyone. I wonder how new caps on the crossover would impact the sound? The tweeters are fine so are the woofers. Just don't sound crisp if that is an audio file term.

If I remember correctly,  Jon's favorite was the TC60

I heard S. Angelus on several occasions and while it was an exceptional speaker for the price a number of years ago, I feel replacing it with something new (or even a vintage speaker of better quality) would be a better choice- they just sounded "indistinct".  Even many small monitors these days get exceptional reviews while lacking just a bit of low bass- and more often than not, this is not regarded as critical on many types of music.  

He could probably make some money if he resurrected the brand and did Mark II versions of the TC50 and the Angelus.

It was,  Jon was doing Precision Audio Services and later changed to Precision Sevices.  Jon was very good friends of one of my best friends.  I met Jon through him. 

Wasn't Spica sold to Parasound?

Just went and looked,  here is the last contact info that I had for Jon.... My not be accurate any more, this was 20 years ago. Tim 

Email: John Bau   sales@linearz.com 

Phone: 505-988-5233

PRECISION SERVICES
Santa Fe, NM 87501

John used an Audax  HD12.9D25HR on that speaker.   I don't recall this tweeter using Ferro fluid. Audax still stocks the replacement coils. You can try Madisound,  they don't list it, but they may have it,  Falcon Acoustics in the UK list that they stock it... Then last resort is Audax.com 
As far as the crossover,  Johns parts were average to good for the day,  He used decent coils,  nice resistors for the time.  This crossover used 1 electrolytic and several mylars... A cap replacement isn't too tough and you'd hear it.  

Shadowe how would I know if the tweeter was dried out?

Tweeter dead or ferro fluid dried out?

Google is your friend. There is a Yahoo Spica owners group that could help you.