Radcliffe I am guessing in the UK? The last name "Holland" can be either a Dutch or English name, I am guessing he was probably British, and was never Dutch to begin with. In any case that would be the place to start. If you have a means to go to Radcliffe since he was born there you can try the catholic Church there. The church has a website:
http://www.radcliffecatholic.org/genealogicalresearch.htmThere is a great deal available online, but there is more if you go there in person, and search the actual records. The marriage record you may be out of luck since 1955 does not seem to be available at their records office.
http://www.genuki.org.uk/big/eng/LAN/LittleHulton/StEdmundKi...I am not too familiar with Brittish records anyways and this is the wrong thread to be asking since this is the Netherlands Forum. Are marriage records also held by civil/government records? If so, if you can prove that your Dad has passed away you may be able to get those records. In fact a death record could also yield more information.