Look for the Hollander manual.
It lists which parts interchange between Toyota models for most years.
Old manuals covering the 1970's come up quite often on Ebay.
A trip to the local wrecking yard with a tape measure brings up wonders.
Make up a table like the following to compare what each model has:
For the record, the T10# and T11# series (what an American would call a '74-'78 model) went from Aug 1973 to Aug 1978.
It was replace by the T13# model which went from Aug 1978 onwards.
Australia made it's own version of the RT104 with many local parts (eg rear axle) which lasted until Aug 1979 - a year longer than the rest of the world.
Engines and gearboxes are freely interchangeable with the pickup, Celica and 4 cylinder Cressidas (not sold in N.America but popular in Asia and Europe).
Small caveat that you may have to use the rear extension housing of your old gearbox because different models used different extensions.
If you change engine families (eg put a 13T where a 20R used to be) then you will need to change the crossmember but changing within engine families is fine (eg 20R and 22R can swap).
Beware that some engines are taller than others, so bonnet (hood) clearance should be checked.
The front brake calliper bolt spacing is the same as used on early 1980's pickups with 4 spot callipers.
Works well when combined with a Peugeot vented disc (requires some machining to disc).
Wheels use the same PCD bolt pattern as Nissan and Mitsubishi.
Take care the offset also matches when taking rims from a late model Skyline or 200SX.
External mirrors are often interchangeable.
I recommend the '77 Celica GT bullet mirrors (similar 1969 Mustang mirrors also suit).
Replace the small internal mirror with a larger mirror from almost any later model Toyota (same roof bolt pattern).