You need to get away from the 'digital' mindset, that the data is just read of the LD as some info which is then simply output ot PAL or NTSC. This is not how laserdisc works. I don't mean to sound mean, but suggestions without any knowledge or research are mostly wasted as the reality is so complex that the chance of 'stumbling' across a solution is almost infinitely small. I'd suggest anyone wanting to contribute to the Franken-X0 discussion do some reading and research offline first.
Some background will probably be helpful here.
1) PAL vs NTSC. Its not just the framerate. The big differences as far as laserdisc goes are:
a) Different rotational speed. NTSC CAV = 1800RPM PAL CAV=1500RPM NTSC CLV = 1800 down to about 600RPM, PAL CLV = 1500 to about 500RPM
b) 3:2 Pulldown. This is where it gets frankly amazing. You all know that for NTSC they do the perverse 3:2 pulldown, wherin you use a film frame for the first 3 fields, then grab the next frame and use it for 2 fields, and then start again. (Grabbing the next frame is referred to as 'pulling it down' hence the 3:2 pulldown name. They used to just repeat the 4th frame which gives the awful juddering you can see on some early telecines.
Now to do this on Laserdisc, they player has to know which two adjacent fields actually make up the frame (othewise you might get one field from one frame of film, and the other field from a diferent frame - not good). So how does an analogue system cope with this? Easy, encode the required information in the VBI (the vertical blank interval). When making the disc, you store the info in the VBI, its often referred to as a 'white flag'. When you hit the pause button on a CAV disc, it reads the flag, and the laser assembly actually does a one track reversal (i.e. 2 fields) and can then redisplay the current frame. It is set in the VBI area outside of picture info, or CC info (its at line 11 or 274 depending on the field). If you get it wrong, the pause feature will have a 'jiggling' frame for 40% of the frames! You can see this on some discs. Sometimes just the 'picture number' is used instead, which is also encoded into the VIL.
PAL on the other hand needs none of this, they just play at 25fps, like the way DVD does in that respect. This makes PAL very attractive for conversion as there is no difficult IVTC to contend with.
c) Frequency and colourburst. The frequency of PAL is 50Hz, and of NTSC 60Hz (for this discussion anyway). Laserdiscs are composite video, which in simple terms means a black and white image with a colourburst signal. Even black and white laserdiscs have to contain the colourburst signal. The colourburst signal from PAL and from NTSC are also very different, and because of PAL's encoding, there is no need for the 'hue' adjustment you see on NTSC TVs. On PAL , red is just red - end of story.
d) Analogue Video. Video is stored on the laserdisc on one long spiral of pits of infinitely variable length (the analogue part). For NTSC the baseband CV signal of around 4.2MHz wide is used to modulate a FM carrier signal (about 8.5MHz or so) . This results in a variable amplitude of 7.5Mhz to 9.3MHz, which gives you an analogue rendition of video (Its at this point that it is something near video, but still not something you could directly output to a TV) . It is not digital video, so what is on the disc is not anything that is directly manipulatable or 'interceptible' to turn it from NTSC to PAL.
Now because it is *not* digital, it is actually possible to swap laser transports between different models, and this has actually been done in the past. It also means that laserdiscs are weird and wonderful beasts with analogue braking mechanisms, and all sorts of amazingly bizarre mechanisms to track the spiral and focus etc. They are absolutely not anything like a CD player in that regard, and the video extraction is absolutely not like DVD or VGA - TV for example.
d) Resolution. This is where it gets really interesting for us. In letterbox mode, NTSC discs have a vertical resolution of just 480 vs PAL 576 lins. This may not seem a big deal, but when ou get down to letterbox, that leaves NTSC with a measly 272 lines of resolution! PAL by contrast has 327 available lines (obviously depending on the aspect ratio, but the above is pretty much what you get on Star Wars), so around 20% more. When the baseline is so low this can really make a difference - hence the interest in the PAL laserdiscs as a master.
Now in NTSC laserdiscs, there is no error correction, unlike DVD, so the means of making sure you get a watchable picture are purely analogue. On the X0 for instance, there are multiple output stages to average out any errors, on other players they employ a range of techniques to get a decent picture out the other end.
They are a truly fascinting system, but also horribly horribly complex, and take a non-digital mindset to understand them They actually have a lot more in common with VHS than they do with DVD or CD as far as the video goes.