Hello everyone.
The 1700 was an excellent little deck and more than compared with a Rega Planar 2 at the time - we sold both. The best cartridge for it was the MMC2EN, which opened the sonic window up well. I actually prefer the sonics of this deck to the 'Gram 1800 which replaced it, but that's another story...
When setting the arm, I'd readily agree with the previous posts and to add that the anti-skate (bias correction in the UK) is applied internally with a spring arrangement which is pre-set as I remember. When "floating" the arm, let it return to the right and "0" the counterweight scale with the stylus just level with where the top surface of an LP would be, then rotate the whole assembly towards the pivot until the scale reads 1.25 or thereabouts, which seemed about right for the EN model. If the cartridge is still servicable, the sound should be fine with little if any distortion, right through to side end.
A shame the "new" Soundsmith cartridges are so expensive, but if the deck is in good condition, I'd try to find a new belt and enjoy some good music on it, looking to eBay or similar for a replacement cartridge.
By the way, keep the cartridge warm, as in colder UK weather, especially at this time of year, the sound dulls off a bit if the room is kept below 20 degrees C (well catalogued at the time as I remember).