After loking at your list better, i found a lot of wrong with the resto shaman, feels like you have made a weird mix of a healing set and a mp5 set.
Resto shaman
Head:
https://classicdb.ch/?item=18870 is Bis for stage 1. its also a better item in stage 2, but i guess you are sacrificing that one for the 3 set bonus.
For stage 3,
https://classicdb.ch/?item=21615 is the best, T2.5 is pretty bad overall, its more of a dps set for all hybrid classes.
Neck:
https://classicdb.ch/?item=18723 prebis, although i know that the neck was added in a later patch (1.4 or 1.5) this neck is bis until ZG release, which it then gets replaced by
https://classicdb.ch/?item=19885
Shoulder: I think there are some better prebis shoulders, i cant remember where from DM i think.
for Stage 3, Wild growth spaulders, does not get replaced by T2,5. they are like twice as good.
Cloak: If hide of the wild gets replaced in BWL is debatable. its a 10healing vs 6mp5, up to preferance really.
Chest:
https://classicdb.ch/?item=13346 Is BiS all the way until AQ40, and its replacement is not the T2,5 chest. but
https://classicdb.ch/?item=21663
Bracers: i know you want to keep the 3set t2 bonus, the t2 bracers are probably the worst piece of the set, but it is probably the slot where you lose the least from, so alright.
Gloves: good slot for t2 3set bonus, so looks good.
Belt: looks good.
Legs: Bis for BWL is
https://classicdb.ch/?item=19385, its also bis for AQ and better than t3 leggings, but you probably want to 8set bonus
Boots: best in slot boots you listed for MC, is a drop from the Silithus bosses, and depending on when blizzard release that (wasnt released until 1.8 i think) making the
https://classicdb.ch/?item=13954 still bis for that tier unless ive missed some other boots.
And for tier 2
https://classicdb.ch/?item=19437 are better than the pure mp5 boots you listed. they are even better than t3.
ring: looks ok enough, it all depends on mp5 needs, you sacrifice a lot of +healing for the mp5, but might be needed.
trinket: same as rings, but gotta get that mp5 from somewhere, depends on how much mp5 you need.
weapon:
https://classicdb.ch/?item=19360 from bwl
Offhand: AV exalted is bis all the way to Kel'thuzad.
WHen that is said, i am very +healing focused, and your list is very mp5 focused. both stats needed and that is really a balance each individual player needs to find out for themselves. there is no 100% correct way of gearing for a healer, cause it all depends on individual skill, and the skill of your raid members, and raid setup and more.