In doing some other work to my rover, I discovered that there was a standard (non-skirted) type thermostat installed. I know that the 2.25 petrols are supposed to use the skirted thermostats. I order a skirted type and I am puzzled hast to how it is supposed to fit. Please see my pictures and let me know what I am missing here.

Old thermostat in housing:
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Housing:
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New thermostat in housing:
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New thermostat in house with top sitting on thermostat:
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Old and new thermostat:
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