You can also make a remote battery pack and run the power cable into the "DC in" connector if it has one or you can disassemble the old battery pack and use the connector as a means of connecting a remote battery pack to the radio. We used to do this for hangliding so we could make a more powerful battery pack.

However after saying this, I remember there was isuues with the complex design in the Icom radios that made the dissemble option complex.

Also with the knob on top problem, we used to put some flexible plastic tubing on the knobs to extend them, because you glide with gloves on. Gloves make it difficult to grip a wee knob. This might help a bit.