First of all a standard case unmodified...
Then the case I started last week and a tool I use for getting in at angles that are awkward without it...
This is a Proxon right angled ac mains powered 90 degree hand piece Too large for transfers in the bore but good for getting at the base of the case where the mag housing meets the case for a neat blend...
This shows how it can access the base with ease and at an angle that's lets material be easily removed... I had made a start but stopped to take this pic...
Using rubberised aluminium grinding bits, this after opening the transfer port and blending the mag flange to size the finish obtained is then with a flex drive and about a dozen rubberised bits for each transfer
and a shot of the casing one transfer opening smoothed the other still rough ported... the finish is a contrast tungsten's on one side and aluminium rubberized bits...
this shot to give an Idea how much metal has been removed..
The metal that's been removed is only to allow a better feed to the smaller main transfer that on a standard barrel gets not such a good feed It now has an area about 50 % larger... The port could be bigger all round, but I see no real need to do this, as its only supplying a standard port that has only been enlarged in the feed area down the barrel, but not in the bore... but it could do with a little tidy up in the bore... Maybe later
The reed block has already had a little work done to it the effective area at the tip of the reeds is about 20% bigger and the flow should be quicker through this reed block than a standard and the reeds have been trimmed all round... I posted this elsewhere but as its for this engine I thought I would put it on here..
Standard reed block...
modified block...
Standard reed on left, and modified reed on right, slightly smaller and finished off with fine wet and dry...
This is the barrel that its being blended to, the tansfer feeds already enlarged and matched to the pack piece the pack piece then bolted to the casing to effect a good blend.... This pack piece probably wont be used but another better blended pack piece will be used in the end...
... but this taught me what not to do :smug: ... and I have never repeated these port timings on another barrel since... 
