Signpost cantilever (Classic town and Legoland)

[Takeshi Takahashi]

I've submitted the missing part (Signpost cantilever with Shell pattern) in set 601 as u454p01.
https://forums.ldraw.org/thread-22660-po...l#pid39984
https://www.ldraw.org/cgi-bin/ptdetail.c...454p01.dat

I have some questions about this part and would like the community members' opinions.
1) This part is listed as x454pb01 in Bricklink and upn0252pr0001 in Rebrickable.
On the other hand, there are two parts with different parent part number (bb0107 in Bricklink and 107 in Rebrickable) while they appear to be the same brick shape with this part.
https://www.bricklink.com/v2/catalog/cat...5D#T=C&C=1
https://rebrickable.com/parts/107/road-s...ved-plain/

https://rebrickable.com/parts/107pr0001/...ell-print/
https://rebrickable.com/parts/107pr0002/...ice-print/

Should we unify the parent part number for these three as "107"?

2) I've used part 764 as the substitute of this part u454pb01,
but I couldn't find any real part of 764 in external databases (Bricklink, Rebrickable and Peeron).
There are two possibilities: "I've overlooked the existence of 764" or "The part 764 is only a ghost".
https://www.ldraw.org/parts/official-par...partid=764

[Magnus Forsberg]

a)
There's an unwritten rule that say we should use the unknown number used on Peeron, if there is such a number, but substitute x with u.
x454(Peeron) would become u454(ldraw). In this case you picked x454 from Bricklink. This is the first time I see Bricklink using a Peeron unknown partnumber.

b)
I don't know the history of that part, but I guess 764 is a formerly "unknown partnumber" that have lost the "x" when it was made official.
Read more here:
https://www.ldraw.org/part-number-spec.html#unknown_num
Anyone have this part?

There's part at Peeron:
http://www.peeron.com/inv/parts/764
but no inventory or photo.