AUSSIE MM fan with Q's?!?!

firstly great site - I am so thrilled to have found it.
okay, i have a 210hd130 (in script) with the pre amp valve in the shield etc etc.
the speakers are 10" as mentioned, and have MM stickers/logo on the magnets - are these the standard speakers? and does that mean there alnico? or are they ev's (dont think so)?
i have purchased a 212rh130(in script) cabinet with the large port along the bottom.
what does hd and rh stand for?
the speakers are broken and im not sure if they are MM or not - how can i tell?
and if they indeed are MM speakers shall i get them rebuilt or buy replacements remembering that the need to match the 2X10" in the combo.
and when i actually get to use the extension cab, so 2X10" combo with a 2X12"cab, do i flick to 8 ohm as opposed to 4 ohm when running as a combo?
and is there going to be a volume difference between the combo and extension cabinet - is that a problem? is their a remedy?
am i better of fitting 2 10" to the cab maybe?
thankyou very, very much in advance for any info.