I picked up an older Centurion yesterday and would appreciate help identifying the model. It has been repainted so there are no identifying decals, only a 1970s style headbadge. The specifics:

SN 6R5011. There is no letter in front of the 6. The date code on the Suntour derailleurs is RL (Dec 75) so it appears to be a 1976 model.
Derailleurs are SL front and VGT Luxe rear. 5 speed Pro-Compe freewheel, suntour bar-end shifters

Most other components are SR including handlebars (Randnner), Custom seatpost (26.0mm), stem, cranks (Apex 5 RG with 118 BCD). DiaCompe centerpulls (no braze-ons on the frame) with cable release on levers and with safety levers

The lugs on semi-ornate on the headtube but with very long points on the top and seat tube. As long as on my 77 semi-pro. They might be chromed under the paint but I don't know. The dropouts are single-eyelet chrome without adjustors.

There are braze-ons: top tube cable guides, down tube cable stops, water bottle bosses (one pair) and a BB rear derailleur cable guide.

Any guesses on the model and tubing type?

Thanks