OK, the additional picture helps. Based on the 600EX components and Nishiki stay caps, in conjunction with a Lovell repaint, it should be a Canadian market Nishiki Competition. The absence of top tube cable guides indicates it's pre-1982, while the 600EX indicates no earlier than 1978. While the wheels themselves are replacements, the 700C size appears to be correct based on clearances and pad placements. 700C wheels were new on the Competition for 1981. The frame characteristics are consistent with a 1981 Competition This is early enough that it could have been repainted by Lovell prior to his tragic accident in 1983.

Was the serial number punched out before or after the repaint? Tampered serial numbers are typical of stolen bicycles. I wouldn't think that Lovell would want to get involved by painting a bicycle that might be stolen. However, if Lovell had repainted it, I could see someone thinking it was an actual Lovell, stealing it and then trying to remove the serial number. Maybe this passed through the hands of infamous GTA bicycle thief Igor Kenk, as well as Jocelyn Lovell's?