Which could be the smallest mechanical film SLR from Canon?

Recently I've been using a very nice FTb ql, but I'd like to know if during those days Canon also made a small, full featured all mechanical SLR, in the same league of its competitor like the Nikon FM2, Olympus OM-1 or Pentax MX.
I know that the AE-1 hit around that time and is small and nice but it also has an electronic shutter… So which could be the smallest mechanical Canon SLR?

That Canon 35 mm SLR and Olympus OM- series cameras are part of some dead end camera systems. NONE of the lenses from those cameras can be used with modern dSLR cameras.

ANY Pentax K-mount camera lenses can be used with current Pentax dSLR cameras, but you will have to do some research to see which was the smallest.

Any Nikon advanced dSLR camera can use almost all the the F-mount lenses, even manual focus Nikkor AI lenses

Of the modern Canon EOS 35 mm SLR cameras, the "Rebel" cameras are probably the smallest.

Of all the 35 mm SLR cameras, the Olympus OM series are the smallest systems, but as mentioned are part of a dead-end system.

Nikon made a small 35 mm SLR in 1979 called the EM and it can use all Nikkor lenses but for the auto-focus ones. Two other small 35 mm SLR cameras made by Nikon were the FG in 1982 and the FG-20 in 1984. This was a time when electronically controlled, mechanical shutters were first being used.

The T60 was probably the smallest, but I don't think it was mechanical.

I think the FTb is the smallest all-mechanical SLR Canon made. Only the F-series are mechanical, the A-series and T-series are electronic. All of the amateur F-series are about the same size; the professional F-1 is larger and heavier.

Well, good question… Why did Canon never manufacture a small mechanical SLR?
As far as I can see it you have two things to do: First, keep and enjoy your nice FTb, which is as solid as a F-1, and probably will last for decades… Second, If you want or need a smaller mechanical SLR, all the models you mentioned are very nice, with Nikon's as always being far superior in terms of quality but not necessarily in terms of performance and results. The Om-1 and the Pentax MX are really nice designs as well as strong performers, but not as durable as your FTb of course!
Someone mentioned the polemic Canon T60, which is a Cosina made body that only takes Canon FD lenes and shares its chassis with cameras from other brands like the Nikon FM-10, the Olympus OM-2000, the Yashica FX-3 and lots of Vivitars. The problem is its weird 'modern' plastic/rubber aspect, which is not as classic as the Yashica FX-3 for instance… The Nikon and the Oly are somehow in the middle of the classic-modern path… Don't go for a Vivitar.