Try here: http://www.toilettanklids.com/seats.html
In the Garbage! Why would anyone want to locate a 46 year old faucet from a defunct manufacturer? Replace it!
I have bought many UR parts at www.lockeplumbing.com they have more than is on line cause i emailed them about my part and they had it.
I'm not familiar with this toilet, but you might try PlumbingSupply.com. There is one for an Elger that might work.
Universal Concepts, Kilcoole, Wicklow
Most auto parts store sell a replacement cable.
I found a white square toilet seat with a 10" bolt at PlumbingSupply.com
Maybe Rite-Aid or walmart... a place like that
If you do not want to change the drain pipes, you will need to install a toilet that matches the existing rough-in. If you can find a brand name and model name or number you can order an exact replacement or cross-reference to find a fit.
Update 2/2010 tilche seat are available call 914-963-5110
Found thess sites, which might be helpful; good luck! http://www.plumbingworld.com/colormatchtoiletseats.html http://www.toilettanklids.com/seats.html
Update as of 2/2010 more tilche tl-235 seats are available call 914-963-5110
You can find toilet parts online from Amazon. Amazon has a large selection of toilet parts from various manufacturers that can be used to replace any broken toilet parts.