One of the official pokes (42183,11) to move the invisible object from First Landing to The Hall, well it works OK but the object is still invisible.
To be fair it is in Willy's direct path unless he is jumping.
After a little thought about this, it would be very easy to give it a shape, however a bit of care must be taken with a choice of shape as the object is actually 'floating mid-air' rather than on the ground so not all object shapes would suit.
Looking at a few objects that are already 'floating' the ones used in West Wing Roof seem the best choice as:
1. They are only 5 instead of 8 bytes
2. They are already a 'floating' object
Having already applied the 42183,11 poke, simply add these:
Or if you prefer you can use a little bit of Basic to 'copy' those bytes:
FOR N=52196 TO 52200 : POKE N,PEEK (N+11520) : NEXT N