Many of my albums are listed in iTMS but match is uploading my local music

Question

I've been an Apple user for over 15 years but for all its simplicity Match more or less stumps me so I am coming here hoping one less muddled can explain this.
I have a library of 21,000 and after its initial trawl iTunes Match seemed to indicate it had found about 4,000 matches. Even for my diverse eclectic taste I thought this a bit low. Shortly after I noticed that a number of albums I had bought from iTMS that were either still protected or were unprotected had been marked for upload. Then looking at my purchased collection form emusic and cd's i had converted many of these too were marked for upload despite any being available for download on iTMS.
It has so far taken a week to get my music uploaded as far as now having more than half of my library on iCloud servers and i've been through all the usual hang and drop nonsense getting that far with about 9000 more to be uploaded. Once I have finished my upload I was hoping to replace a number of cd's and iTMS sourced tracks from iCloud but this does not appear to be the case.
Is there any tip or solution to make iTunes Match associate these albums it is passing over or must i just lump it and accept my low quality copies are not going to be improved which is not what Apple was offering me when i signed up for the service. I am not that fussed about the emusic music as being in similar quality MP3 there may be little merit swopping for AAC copies but it is narking me that I have music iTMS sold me or did not allow me through iTunes Plus to upgrade from protected that are there on iTMS that I cannot take advantage of the upgrade offer.... ??? feel fre to answer or point me to other posts covering this issue.
Adrian
PS I too am suffering the now widespread Beatles 'She Came in through the Bathroom Window' iTunes Match that it seems unable to match!!!

Answer 1

Thanks Michael and Keith.
I had done a read around at many of the usual candidate mac support sites but nothing really un-muddles my mind about this. I have enabled iCloud Status in my playlists and I have set up a number of smart playlists to assess and monitor the process of the upload.
I have 21555 'music' files of which 9246 songs listed as "matched"
Of the 13083 songs currently not "matched' 1642 are listed as "purchased" 2053 are "Uploaded" 9341 are "waiting" 3 are "ineligible" 24 are "Duplicate" 5 are listed as "Error"
In my iTunes Purchased smart playlist tells me
of 1837 songs 20 are "matched" 1613  are "purchased" 163 are "waiting" or "uploaded" 35 are "inelegible"
1561 Purchased AAC files 3 are "matched" 16 are "waiting" and the rest "purchased"
257 Protected AAC include 16 "matched" 71 are "purchased" 5 are "uploaded" 134 "waiting" 30 are "inelegible"
Of the 3135 eMusic songs
2259 are "matched" 871 are "waiting"
I have only so far seen 3 albums with the download icloud icon and the 3 are from the iTunes Store and they are all of the same quality and type as the copies I already have.
If nothing else how do identify those songs iCloud is going to rely on songs held by Apple already and for those songs that are of a higher quality or have removed protected status how are they downloaded?