Here are pics of my Spaceliner numbers. It is extremely hard to make out in person as well as on photos. It has a clip for the tank and had the forks of of a springer all though the rattrap had been removed.
Thanks for your help,
Doug "Sludgeguy"
Hi Doug... sorry but I've been away for a few months, so I wasn't able to get my two cents in.
JD is on the right track, I think, when he suggested your bike probably started its life as one of the non-Spaceliner tank bikes produced by Murray under their own brand or for others. Since then, yours has had a 1st gen (64-65) Spaceliner rear rack added, as well as a 2nd gen (66-68) Spaceliner chain guard. Since the model number isn't legible, the reason I think the frame is not from a Spaceliner is because of the position of the tank front mounting tab on the head tube... it's too low. I couldn't see the rear mounting tab in your pics, so I can't verify the rear tab design. I have posted a couple of pics below of the mounting tabs from a chrome straight-tank Spaceliner I have so you can compare them to what you have (more comments follow below).
Based on the front tab position, I think your bike was originally probably something like a Murray Astro Flite or a Western Flyer Cosmic Flyer (or possibly even something like a JC Penney Foremost). The higher front mounting tab on the Spaceliner means the tank sits noticeably above the down tube, whereas the tanks on the others sit flush with the down tube because of the lower mounting tab position (as found on your frame). My final comment is that, based on the pics of your rear drop-out where the paint was missing, it appears your frame isn't chromed and was probably red originally and subsequently covered over with a spray bomb. FYI, both the Murray Astro Flite and JC Penney Foremost were available in red paint, so it's a strong possibility either of those might be yours... most likely the Astro Flite.
Here are some comparison shots of how the tank locations differ between the Spaceliner and the others due to the difference in tab position. You can also see how the higher tank position of the Spaceliner results in the twin top tubes coming thorough the chrome instrument panel unlike the others where the tank and instrument cluster rest below the top tubes. The Spaceliner is the
only variant of this 'family' of tank bikes where the top tubes come through the tank and instrument panel rather than over top.
SPACELINER
WESTERN FLYER COSMIC FLYER
MURRAY ASTROFLITE
And here's a promotional page for the '63 Astro Flite, in red, which I think is most likely what your bike was originally before it was repainted and had some Spaceliner parts swapped onto it.