This item is made to order, so please expect a lead time of roughly one month.
Photos need to be updated, I have made some improvements.  The function remains the same, it simply has rounded edges now. 

Before you purchase this item, please understand that some DIY is required to remove the Heine condenser's dovetail mount.  This is necessary to raise the Heine adequately, allowing phase annuli to overlap.  This is also necessary for oil immersion.  The modification is 100% reversible and non-destructive.  

To remove the dovetail, use a spanner wrench.  Please see the photos for a guide.  (photos coming soon) 
If you cannot remove the dovetail, please find a workshop to do it for you.  You can also try and heat it up a little, use lighter fluid, or make a better wrench tool with wood and mount the condenser onto a vise.  I will be designing one of these and I will share the schematic.  Please message me if you have questions. 

This was designed based on a BH2 adaptor I purchased.  It works for BX and AX microscopes, it works for IX microscopes as well using an adaptor (IX-ADUCD), it will also work for the excellent Olympus BH2 from the finite era.  It should also work on modern Nikon microscopes as the dovetail specifications are similar. 

I can offer to design ones for other models based on this.  I can guarantee mounting but I cannot guarantee adequate clearance.  To mount this onto a BX/AX microscope, the condenser holder needs to be lowered enough first. 

High quality CNC. 
LEAD TIME IS 4 WEEKS, then postage.
(The estimate is very conservative, it should not take more than 3 weeks typically.)
CONDENSER NOT INCLUDED. 

Transparency:
Cost breakdown...
- CNC cost: ~$60 (will be much cheaper if I make 10 but I am not going to)
- Shipping to Australia: ~$30
- eBay fees: ~21% (yes, it is that high)
So the raw cost is around $120.  I will be profiting around $50. 
I will not be drop shipping this product because it must be tested to ensure functionality prior to postage.  I also need to provide the nylon-tapped set screws and the hex key.
Naturally, it will be faster if you are in Australia. 

My adaptor allows the filter holder to be mounted, you need to unmount the field lens on the bottom to use the adaptor. 

Steps:
Unscrew the bottom field lens of the Heine condenser.
Slide it into the adapor, with the protruding adjustment screw portion sitting comfortably in the slot. 
Tighten the three set screws using the provided hex key.  Please keep the hex key, it is a high quality ballhead type made from brass. 
Screw the field lens back on. 
(I will record a video when I have the time.)
Please follow the usual steps to align for phase contrast microscopy.  You will get better images by using the oil immersion top lens and mating it to the slide with immersion oil. 

Produces brilliant phase contrast results, something that is unobtainable with modern finnicky phase condensers. 
The Heine condenser can also be used for darkfield and oblique contrast, a modern phase contrast condenser cannot do darkfield with objectives of NA above 0.75 unless you use a thin slide. 

Shipping:
Shipping costs adjusted for travel, materials and handling.  High value items insured. 
I do ship globally.  Will combine postage.
Sometimes, eBay does not combine postage costs.  Pay anyway and I will refund the difference, or wait for an invoice.  I can also do custom listings for you that include all the items. 
AusPost Standard or DHL e-parcel (usually 3 weeks)
Express offered, I can do UPS or FedEx, I can use your postage labels, enquire.

AusPost Parcel Post to anywhere in Australia. 
Usually ships in a day, however, I do get busy at times and go on business trips, so please allow up to 7 days.

Returns and refunds:
This is a custom, made-to-order item.  Because of that, I will not accept any returns or refunds with some exceptions.  If the item is lost or damaged during transit, or it does not function due to craftsmanship.  Please ensure that you are capable to perform this DIY, and you are able to remove the flat dovetail plate.  

Customs: 
It is the buyer's duty to contact customs in case of items being held for clearance.  I will provide invoice upon request.  
An item held for too long will be returned.  I will not refund postage in this case. 
It is the buyer's duty to contact me regarding any special customs provisions the destination may have. 

Photos:
All photos were taken with a mirrorless camera and adjusted white balance using a grey card.  Minimal processing.