Whilst not directed to me I will answer
I really like QR or Take down mounts and have most of my rifles with them from cheap systems and types to the expensive Apel mounts. The advantages to me are easier rifle cleaning witht he scope removed and when travelling especially if not by my own car then the scope can be carried safely be carried on ones person. Using Air line travel this is essential as far as I am concerned
Then there is the old reason of being able to use the iron sights should that be required for any reason. I also try to sight in the irons to the load I am using Just In Case
The Weaver sytem although it look dawn right homely works for this as does the old parker-Hale rings and bases. I am not enamoured with them though but at present am stuck with them for some old BSA sporting rifles I have until I can coem up with a suitable alternative. The Millet rings are pretty awful, have tried a set on a 1st pattern Monarch in 270 win and the scope moves forward no matter how tight you get them
Guess I need to try some Lynx rings and see if they work
Hilver made some bases to take the Tikka (type) rings and Ernst Apel makes roll off which also return to zero as well as their EAWswing mounts
The Leupold QR lever mounts I have on a P-H 1200 Super work OK but require much fitting (the bases did not get anywhere near the contour of the action unlike the Apel rill offs I have on another P-H rifle) and the bases are too high to allow the irons to be used so I doubt I will bother with them again.
I also like steel mounts which are much better in my opinion than alloy ones and if possible mounts with windage adjustment so I can center the scope especially the older ones which are moving reticle and not image moving.
Now in answer to this :-
Will Leupold QRW rings work Weaver #421 and #35 bases ?
if not can you or any other poster provide recommendations for a two piece base system that can utilize quick release rings
for a mod seven ?
As I said the Leupold lever operated mounts have very high bases so check if this will work for you the ones I have use a cam on a pin to lock them and will only fit the special Leupold bases but I understand leupold do make a lever Op weaver type ring but I ahve never seen the personally or used them I think they call them the QRW?