When I started fontmaking I used an older software program named Softy. I produced some fonts and published some of them on the web.
After using Font Creator for some time and updating the original Softy-produced fonts using Font Creator I came to the conclusion that the best thing to do with each of the older Softy-produced fonts was to start a new font in Font Creator 5.0 and then open the original font in Font Creator 5.0 and then copy the glyphs one by one from the original font and then paste them into the correct place in the new font. This meant that all of my original work in producing the artwork for the glyphs was not wasted, yet the underlying flags were all set as for a brand new Font Creator 5.0 produced font rather than having Font Creator 5.0 very courteously preserving the underlying flag states of the original font.
So, maybe that solution might be of help to you.
It is possible to copy more than one glyph at a time, yet that technique needs learning, so maybe one at a time is the best way to get started.
If you were to start a new font using Font Creator 5.0 and then copy the glyphs one by one from the original font into the new font, then that might be a good position to achieve and then you could begin to make your adjustments. Certainly there may be some adjustment of the metrics to be made, yet those could be copied (by reading from the original and then keying into the new font) from the old font and if there are problems then maybe you could put the new font into your webspace and hopefully someone here could advise you.
In all of this, the fact that the glyphs are 581 font units wide does not help with rendering on a PC, as ultimately the system will need to decide how many pixels to use and the formula for a PC running under Windows is (4581)/(32048)*point size which is 0.378255208333333333333333333333333 times point size which for 12 point is 4.5390625 which needs rounding to a whole number!
So, depending upon which point size or point sizes you wish to use, it might be a good idea to try widening the glyphs a bit.
If you wish, you are welcome to have a look at one of my own fonts which has a similar sort of look.
http://www.users.globalnet.co.uk/~ngo/TOL.TTF
http://www.users.globalnet.co.uk/~ngo/TOL2.PDF
There are some notes about the font in two posts of 30 April 2005 in the following thread of the Gallery forum.
http://forum.high-logic.com:9080/t/fonts-in-development/820/1
I hope that this helps.
William Overington