Searching Colorflow is a good suggestion, Some variation of a J.C. Higgins is likely how your bike started life and you should find plenty of pictures of similar bikes.
If you are planning to restore the bike as a tribute to your father there may be more than one ?ideal? to aim for.
If he received the bike brand new then you could go for a replication of the bike as it was brand new from the factory. If your father got the bike second hand with the replacement crankset, or if he is the one who stripped the bike and changed the crank, then it may be more of a tribute to him to replicate the bike as he owned/modified it. If you can find any old family photos of the bike they would be helpful in determining how the bike was set up in the day.
If you choose the restoration to as-new route you should be able to find a serial number stamped in the bottom of the crank hanger. If you post the number someone on this site may be able to pin down the build year for you. One observation I have made regarding the Murray frames like yours is that the early frames have a different seat clamp designed for a smaller diameter solid seat post. On later models the clamp was changed to accept a larger diameter tubular seat post.
If you decide to restore the bike to as-new factory condition you will need to decide what year, model, and color the bike was originally and then acquire all the correct Murray sheet metal to replicate it. There are a lot of variations so determining the original spec. for the bike may be the hardest part of the project. On the bright side there are a lot of Murray bikes and parts available on the internet so getting what you need may add up in dollars but nothing is difficult to find.
If your father built the bike to his taste, you may already have everything you need to build your tribute and all you will need to do is clean up what you have.
Either way, you have the original frame that your father used which is more than many tributes begin with.
Best of luck with the project, and please keep us posted on your progress or let us know if you have more questions as you proceed.
