I'm sure you would notice the difference, I assume you bought the deck you have because it sounded better than a Planer3? ;0)
The alternative would be to get a new AC motor and external PSU. You can buy the motors new, can't remember the name of the company who sell them but I can find it. You need to swap the pulley over and fit it but that shouldn't be too hard.
One of the best LP12 supplies is the Norton Air Power and thankfully it's also fairly simple so you can build one yourself! The parts will cost about £80, depending on where you can get them, and I can give you a circuit diagram and instructions.
Doesn't the PT Export have an AC synchronous motor like the LP12? It might be the same one, they used it in a few decks, and you could pinch that. Alternatively you could sell the LP12, even as parts, and use the cash to let the Funk Firm invigorate the Pink.
It's all personal obviously but I don't like the Lingo. In my opinion Linn went down the wrong road round about then and started 'fixing' all the things that made the LP12 what it was. I had a Cirkus in one of my LP12s for about five years before I took it out and sold it, technically better, musically wrong.
I have a push-on adapter for 45 but hardly ever use it. Unless you've got pile of 12" singles there's little point as 7" singles sound totally crap! There's no way I'd buy a PSU just because it can play 45s, especially when the PSU in question is really expensive and not the best sounding in the world, and I can build a better one for £80!! ;0)
I keep thinking of selling my second LP12 and it just sits there gathering dust, might even sell it as parts. Would love to get another Audio Technica AT OC9, I loved that cartridge, preferred it to the Troika.