740 grills and Volvo 'stripe'. Wheel

Hi, I am new to this forum, having owned a 740 estate for three years. Now I have 'discovered' this forum, maybe some members can help me with a few queries in respect of the 740's which I cannot seem to solve on the Internet. My 740 has a chrome horizontal lined grill with a long Volvo stripe, which extends almost corner to corner on the grill. I thought this was unique to the 740, but have seen countless 740's with shorter stripes and plastic grill which is made up of small squares. Similarly there seems to be a inconsistency with the plastic wheel hub covers. My 740 has plastic covers with 15 spokes and 'Volvo' in white lettering, yet other 740's have 15 spoke chrome wheel covers with a separate black metal inserts with 'Volvo' written in chrome. Why were 740's given both 14, and 15"tyres? Why did Vovo decide to run a numerical sequence of 740, 940, and then back to 850.

I have the option of buying an 'egg crate' from a 1995 US-model 940 turbo (which used the same front end as the late 740) from an American friend. I think it'd look great :)

Thanks for the replies. So the egg crate grill has a shorter stripe? (What is the correct name for this?)