Attn: Speaker DIY expert

Watch out with inductor replacement. They will likely have a different DCR which can have a negative affect. Stick to caps and resistors. A good mid budget upgrade might use Mills resistors and Sonicaps. It's always a little tough to find exact cap values. Crossovers aren't that complex and don't require a PC board. You can point to point wire them on a piece of nice wood. Glue or wire tie the caps down with a deflex pad under them. Good luck.

ET

Look up Solen electronics for parts
Also look at Parts Express for ready made xovers

The above answers are all good.

The nicely priced sonic caps are great especially when bypassed with mundorf Caps (silver in oil are good, but the gold ones are amazing if you can afford them). On their own the sonic caps can have a slightly plastic quality although great dynamics and detail. Bypassing with a mundorf 0.1mf or 0.01mf makes for a pin point image with very rich natural texture.

Try the Caddock metal film resistors. I have used the mills, but once burned in the Caddocks are more coherent and have less noise.

Alpha core copper foil inductors are stunning too. The DCR value may be different to what you have, but I doubt dangerously so.

Whatever you need can be found here:(http://www.percyaudio.com/Catalog.pdf) And Michael will also match whatever you order within 1% tolerance. I've dealt with him for years and have yet to be disappointed. Normally I use Vishay Bulk Foil resistors in projects, but actually wire-wounds are known to be quietest. Alpha Cores are the best inductors around, but(as mentioned)a resistance mismatch can cause a shift in your roll off points. The Percy catalog will give you a lot of other ideas also(cabinet damping, binding posts, internal wiring, etc.). Have fun!!