I have a lot of (old) Linka moulds. They can be very useful, for buildings and background walls. ScaleCast took up the the reigns of the long dead Linka brand (in the UK) and have been offering the original designs again and have been developing new moulds over the last few years. Although traditionally OO scale, they have just announced they will soon enter the O gauge market with some offerings! https://www.scalecast.co.uk/store/c34/O_Scale.html
Apparently Dundee will need moulds like this when he builds the next couple of Another Bridge sections... I could threaten him with a few more bits of rolling stock.