The Hercules was introduced in Spring 1959 and it was initially fitted with
a Villiers 7F 2-stroke. It is clear that A-V added 4-stroke versions after that -
in the early 1960s. On these forums we have seen both LAV30 and the earlier
GEB Kirby engines (see links above). It is therefore not impossible that a
Briggs version would have been offered.

The trouble is that - if the Vi-Cat chassis was original - it would have to
come from the late 1950s. The reason for this is that by 1960 the issue of
height adjuster design was all but settled.

There was experimentation with a number of different designs from about 1955.
The main designs were via a single point lever (championed by Minter); the
other was via the single point rotary knob (championed by Victa).

All manufacturers agreed that a single point on the mower for adjusting all
four wheels was the goal. By 1960 the odds were in favour of the lever and
segment - it was simple (few parts) and cheaper to manufacture. Out of the big
players, only Pope would persevere with levers on each wheel (American style),
albeit with accurate multiple height settings. Pope would succumb to the
superior lever and segment design within a few years.

There are only two cases I know of a two-point system. A version of Austral
Villiers Adaptomatic used a rotary knob at front-centre and rear-centre.
The last version would have just the rear-centre knob (single-point) to
adjust all four wheels.

The Scott Bonnar Model 31 had an even more bizarre version of the two-point.
It had rotary knobs on each side - each controlling one side of the mower!
The great Model 35 would correct that 'What was he thinking?' moment.

The Vi-Cat presents as having a two-point system, via levers mounted at
front and back. The levers, that appear to be made of spring steel, look
straight-off a Victa from the early sixties. Have a close look at those
plastic handles.

The levers operate against alloy brackets that have been clearly welded to
the alloy frame. Adjustment is achieved by loosening the locking knobs and
moving the levers. It is a very awkward process and the levers at each end
look like something one might see at a railroad siding. For me, total
fabrication! (pun intended)

Conclusion
My best guess is that this intriguing mower started life as a Austral
Villiers Hurcules from the early 1960s. It may well have been fitted with
the Briggs 8 Series as these were being used on AUS lawnmowers of the time.
Clearly the base was designed to take a 4-stroke, regardless of make.

I have argued that the unusual two-point height adjuster on the Vi-Cat
cannot date from the 1960s, but only from that period of experimentation
in the mid-to-late 1950s. This suggests, not that the engine is not original,
but that the chassis base has been seriously modified at a later point in time
(perhaps decades). I believe this lawnmower to have once been a 1960s Austral
Villiers Hercules that has been modified by someone with great competency, but for
unknown reasons.

I am hoping Sir Bat will give us clearer pictures of this machine; engine and
chassis. Numbers should still be found on the cowling, and I am perplexed that
Sir Bat has said there are no serial numbers on the Briggs. Perhaps that dark
paint conceals vital information?

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