actually it could be a Murray Solar Flite, from 64 to 66.
Without seeing the decal on the top of the headlight, or the serial number you can't tell if it is an Otasco branded Murray or not.
If it is an Otasco, they sold the Lancer, with this style tank, from 63' to 66' when the new style tank came out.
The Otasco model would have 54X6. at the beginning of the serial number.
Here is a page from the 1964 Murray catalog, introducing the Solar Flite, (which is a Y54 in the serial of the Murray), also a couple shots of my late 1963 built for 1964 model year Otasco Flying O Lancer.
Aside from the serial number and branding, the Solar Flite and the Lancer are identical bicycles
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