Being a DR 500 and 400 hoarder , they are very similar and thats were you need to be carefull  ;)on the 500 the nuts & bolts go all the way thru the cush drive in a close pattern were as the 400 are located on lugs and are held on by countersunk allen heads  with nuts  
the legs are longer but don't pose a problem ......Dr 500 years   1981 - 83 
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