Completing the Non-precision approach as a Visual Approach

I'm inbound on the final approach segment of the VOR-A approach at T82
(Fredericksburg Texas):

http://www.myairplane.com/databases/.../T82_vd_gA.pdf

At about 3 miles east of the airport I'm at the MDA of 2460 MSL ("766 AGL"),
mostly in a 700 foot overcast. Through a break in the clouds I clearly see
the airport-- the visibility is about 7 miles.

I descend 166 feet and am able to remain just under the cloud deck for the
final three miles, fly the right hand pattern for runway 14 at 600 AGL, and
land.

Was my descent to about 600 AGL (a) illegal because of 91.175c and/or some
other FAR, or (b) legal because I have now in effect "converted" to a visual
approach and/or am now in uncontrolled airspace (1 mile vis and clear of
clouds).

Mind you I'm not saying I did this last Tuesday, but I might have thought
about it if the conditions had been just so.

Cheers,
John Clonts
Temple, Texas
N7NZ