I assume you have 3-1/30 and not 3-1/130.
3-1/30 is from the V17 software disk, it is the 'old' full screen software. You could update to 3-1/63 (the V22 software disk) then you will get a more modern look. Will it be 'faster'? Route planning is a little faster, screen rendering of menus etc. is slower.
To do a software update you will need a V22 (or higher) software CD which MUST be an ISO Mode 2, Form 1 disk (if you don't then the MK III will lock up on you and it's difficult to eject the disk), you'll also need a Key CD to permit the update to the split screen software.
To get a real improvement, upgrade to a Mk IV Nav computer, cost about £300 from e-bay minus what you can get for the MK III (£100 or their abouts).