What would you do? Minolta Hi-Matic G shutter problem

The Hi-Matic G is a great little auto-exposure camera, but this one has a problem.

The camera has a two-blade diaphragm & shutter combination. That's right just two blades act as the aperture and the shutter in combination.

Depending on the ISO and the light, at f2.8 the shutter speed is 1/30 and as things get brighter the combination changes gradually to f14 at 1/650s. A needle in the viewfinder points to the combination that will be used -- but the needle can be locked by pressing the shutter release slightly, offering some manual exposure control.

The shutter/aperture works great at 1/650 all the was down the 1/125, but when the speed drops to 1/60, the shutter opens fine, but closes very slowly.

The two blades are clean as a whistle, so there is something else that is gooped up.

The top and the bottom plates would be easy to take off, but the shutter/aperture is in the back of the lens -- all of the glass (4/3) is in front of the shutter/aperture.

How would you approach this problem -- other than buying another Hi-Matic G?

I've not had to take apart my G yet so can't help with internal woes, but just confirming the obvious first: are you using a fresh battery and is it a Wein Cell, hearing aid battery, or something 1.5V instead of 1.35V?

Yes, it's the correct battery and the needle responds correctly to light. I'll also add that when I switch over to "FLASH" mode (1/30s), no matter what GN (f-stop) is selected, the shutter/apertures opens correctly but is very slow to close -- just as in Auto-exposure mode.

I'm not going to spend much time with it, I've got a very nice G2, and expect delivery of a GF in a couple of days. The GF has three, manually set aperture settings (f4, f8, f16) that are Waterhouse stops, and two manually set shutter speeds (1/30 & 1/125), so what could go wrong?

I would fix it. Have fixed them in the past but they're not easy to work on.