Try having a look at this website, some nice pictures & info on the different looks of the over lapping Tiger I wheels & suspension system,:
http://www.alanhamby.com/suspension.shtml

Besides weather conditions, I presume this answer from the website is also valid for why you might see less wheels or different looking configurations ...
<div style="margin-left: 40px;">
To reduce costs and make production easier, new steel wheels were introduced in January 1944.
Because these steel wheels could handle heavier loads than the earlier rubber-tired versions,
the outer row of wheels was left off, resulting in 2 wheels per axle or 16 per side.</div><div style="margin-left: 40px;">
Wheels shaded black were removed in January 1944.
</div>

~ Craig ~