Believed to be a BSA A7 or A10 oil tank with gauze filter.Rusty but solid. Inside appears oily.
BSA A7 A7SS A10 S/ROCKET R/ROCKET RGS OIL PUMP CIRCLIP - 42-0158 - 67-1390
2 BSA MOUNTING RUBBERS BSA A7 A10 antiroll fuel petrol tank rubbers 42-8052 new
BSA ALLOY BILLET SUMP PLATE WITH MAGNETIC DRAIN PLUG FOR BSA A7 A10 A50 A65
BSA A7 A10 CRANKSHAFT BEARING ARIEL 650 1954-1959 67-0670
stainless steel HUB COVER BSA A7 A10 WHEEL TRIM 42-5843 8" for 7" full width hub
BSA A7 / A10 CYLINDER HEAD BOLT SET (IRON HEAD) - 00-0122