The second hand elbow arrived today in sound but very dirty condition. However, whoever removed the part cut through a small pipe with snips and ruined the pipe. The remains were difficult to remove which will require me to attempt to salvage the pipe from the elbow presently in service on my car and fit it to this elbow once I have carried out gas flowing modifications..
These next images are posted to help Jon when he removes the elbow on his car for parts replacement around the supercharger and general area. Similar images will be posted on a thread I have running and will eventually show the process of charger removal and modification.
This shot looking downwards depicts the elbow and shows the large throttle body mount secured with four Torx bolts. A gasket sits between the body and the elbow. To the left is the smaller by-pass outlet upon which a mounting plate sits complete with a throttle plate and a pressure driven actuator and drive rod link to that throttle plate. I expect to find a gasket between the two parts. A small vac type 1/8 ID inch stub pipe with a rubber pipe is to the centre bottom of the image. The pipe on this elbow was not unexpectedly a loose fit on the stub pipe and will need replacement. The Manifold Air Pressure sensor was to the bottom right ( removed for cleaning) and fits to the elbow with two Torx bolts and a sealing o-ring. The sensor nose pokes through into the elbow directly under the throttle body throttle plate and senses air pressure (negative) below the throttle plate. Several large air pipe stubs also exit the elbow.

This shot shows the elbow mating face to the back inlet end of the charger. A metal rubber coated gasket sits between the two castings.
This internal detail shot shows the huge mass of congealed heat baked crank case breather oil residue which collects in the elbow. It is as hard as road tar and difficult to be move because of its solidity. It can be brokenen up with a screw driver and then softened with thinners. It is a very sticky substance indeed and far harder to remove than you would first imagine. I used acetone and a short length of soft copper 8mm pipe as a chisel to remove this obnoxious mass from the floor of the elbow.
To the rear of the elbow is the EGR valve pipe which feeds into the throttle body. A shim metal crush gasket sits between the pipe flange and the throttle body. I believe two 10mm hex bolts secure the three parts together, The throttle body removal affords access to those bolts. Access is tight. At the base of the elbow is a horizontal threaded lug to which I believe a metal steady plate for the elbow is mounted. Again, expect difficult access.

After detergent cleaning, I further subjected this elbow to a dilute hydro-chloric acid and paint brush cleaning session. I hate working with dirty parts and I attempt to remove as much grot as I can before reworking or modifying any parts. This image shows the outlet end of the elbow with a modified gasket laid over the elbow face. The mods were suggested by Powerhouse Automotive who are experts at supercharger modification. Of note is the 6mm lowered bottom floor face of the modified gasket. The bare metal of the elbow showing within the gasket will be machined away with a die grinder, thus significantly opening up the air flow tunnel within the front face of the elbow. Further matching machining of the supercharger case will be carried out to port match to the elbow. In addition further metal removal and gas flowing will also take place and will also clear further outlet areas of unwanted metal.

This image shows the gasket atop the elbow on which the throttle body is mounted. Once again a significant restriction is noted within the internal circumference of the gasket. Approximately 2-3mm of excess metal obstructs the passage of air directly under the throttle which saps the engine of torque and power.. The lip will be removed as per the Powerhouse recommendation.
Further gas flowing will be carried out inside the elbow which is roughly finished from the factory and can stand a fair amount of smoothing and de-constriction.
My hope is to begin modifying this used elbow tomorrow then setting it aside until I have the time to remove the complete charger for similar gas flowing and re-porting. Getting this second hand elbow for just a few pounds will help me keep car down time to a minimum and reduce the amount of work at the time due to having already carried out modification to the elbow.
Jon`s overhaul of the charger will no doubt require similar work to my own car but probably less the extra gas flowing that i`ve decided to undertake.
More on this job as I progress.
Mike