The crash of RI-003 at Tanjung Hantu in Malaysia is recorded in most Indonesian publications, including in 1950 editions of the AURI magazine Angkasa. Pilots Halim Perdanakusuma and Iswahjudi died in this crash, which was apparently caused by bad weather conditions.
When the Anson wreck was found in the Borneo jungle, the information that it was the wreck of RI-003 was featured by some local media, but based on all other documents published, it could not have been RI-003 or RI-004. Anson RI-004 was based in Bukittinggi during the 1947/1948 time frame, but was then transferred to Yogyakarta where it was captured by the Dutch in December 1948.
As for the Bukittinggi Anson, it could have been rebuilt based on the wreck, or it could be a complete new build, with no original airplane parts included, like the Indonesians did for Catalina RI-005 on display at Jambi.
It should be noted that this Anson livery (paint and roundels) is not accurate for RI-003 or RI-004, since the pentagon-shaped roundels started to appear in 1954.
I'm not sure how good that Catalina mock-up is, but I find it a little hard to believe that this thing - whatever it is - has no original plane parts, seeing it has static discharge wicks and everything.
I tried to measure the fuslage in Google Earth and found a rough length of 12 metres, which is about right for an Anson, and while this doesn't proof anything, at least this is not a scale mock-up or a smaller aircraft.
Anyway, when I was there, for what that's worth, I was quite convinced that it was a real, and old aircraft. I still think the cabin with the seats and the shape of the rear door look especially realistic.
Although there is no proof, I rather like the theory that this thing was built up from the wreck found in (Indonesian) Borneo (Mark is referring to the find mentioned earlier by Jan I'm sure).