I recently owned a Spoiler that i regretfully sold. I have an opportunity to purchase a Distillate that's in very good condition., 32 scale. What is the difference between the two. Electronics?

Very similar electronics, build on the same preamp. Distillate adds a bass and treble cut/flat/boost switch that in the flat position will behave exactly like a Spoiler.  
 
The Distillate body shape is a little different, with a flattened bottom, but a similar length upper horn. Both are standard 32 medium scale. Unless you had a solid Koa Spoiler, they should have more in common than not.

Very similar electronics. In addition to standard Spoiler package, Distillate has boost/flat/cut switches for bass and treble.  
 
Distillate: http://club.alembicguitars.net/Images/16271/24726.html?1138816475  
 
Spoiler: http://club.alembicguitars.net/Images/16271/16327.html?1107554623
 
Someone on this board once pointed out to me, Distillate is very close to modern-day East-Meets-West electronics.  
 
Good luck... I know you hated to let that Spoiler go. Hope this one works out.

Mica is 2 minutes quicker, and far better sourced... =)

The Distillate is a great bass and my introduction to Alembic. There appear to be both a standard Distillate body as well as more than a few that were made with longer upper horns. I know some people have talked about the standard Distillate being a little neck heavy but the body type with the longer upper horn that I had was perfectly balanced for me.

I have an 81 Distillate , the older type. She is truly a sweet little Devil with her single pickup and always seems to get compliments where ever she speaks .

Distillate has some nice, higher end features than the Spoiler - purpleheart neck laminates, brass block under the bridge, crown headstock, and the bass and treble boost/flat/cut switches mentioned. The longer upper horn came in '85 or '86 I believe. I have a beautiful 34'' long scale '86.

Distillate has some nice, higher end features than the Spoiler - purpleheart neck laminates, brass block under the bridge, crown headstock, and the bass and treble boost/flat/cut switches mentioned. The longer upper horn came in '85 or '86 I believe. I have a beautiful 34'' long scale '86.

Here is a pic of the bass I might be buying. Is there a knob missing? Any thoughts on the bass itself?
 

Where would there be a knob missing ? Nice Bass!  It  Looks complete externally . Nice find.

No missing knob... looks like volume and filter with a rotary pickup selector on the upper horn. The row of three switches looks normal. This is an early 2-pickup one with an LED (may or may not be hooked up). Nice looker!
 
Probably will need the electronics RF upgraded - it's not as spendy as the Series I/II but it does cost something as these are completely handwired, even the board isn't printed.

Thank you so much Sonicus and Mica...I am going to get it.

You are very welcome. Congratulations !  
 
 
 Wolf

One thing to note is the truss rod cover is not recessed and there isn't a ton of room between the end of the fingerboard and the bass pickup. That's good - it will have a deeper bass tone for its position, but, some people need more room to play there for their style. Just a heads up there.

Good point Mica....I will be using this for a Grateful Dead tribute...using a pic. I can make it happen. Eventually I will get the Series. Oh, as far as the upgrade is that something a really good luthier can do...one that is great with wiring?