The two 'A' frames, the large flywheel, and the beam adjacent look like castings for a 'Vulcan' beam engine. Can't spot any of the other castings from this engine. Not worth a grand sum I'm afraid, I revently paid just over £100 for a full set of castings.
I pay around £20 for flywheels like those (you have another similar albeit smaller flywheel on show).
As regards the loco castings some dimensions or sense of scale may help identify some of them. Look like a pair of 'Tich' cylinder (rear) cover castings in there near the Vulcan castings, but they may be from a similar sized 3 1/2" gauge loco.
Regards,
Phil.
Edited By Weary on 10/09/2021 21:04:08