When the E-type was introduced in March 1961 it was referred to/badged as simply the E-TYPE, nothing more…
When the 4.2 E-type was introduced in August 1964 it was now referred to/badged as the 4.2 E-TYPE to differentiate it from the 1961-4 E-type that only now became retrospectively referred to as the 3.8 E-TYPE, albeit this was never an official factory model identifier.
When the Series 2 E-type was introduced in August 1968 it was officially referred to by the factory as the SERIES 2 E-TYPE (but was still simply badged as a 4.2 E-TYPE) to differentiate it from the earlier 1961-Sep1968 E-types that only then became retrospectively referred to as SERIES 1 E-TYPE, albeit this was never an official factory model identifier. And thus you also now had reference to 3.8 SERIES 1 E-TYPES and 4.2 SERIES 1 E-TYPES
Then soon after coining the unofficial reference to a Series 1 E-type mostly based on the cleaner looking covered headlamps, slimmer bumpers and smaller above the bumpers side-lamps, you started to get the later 4.2 Series 1 E-types where they were modified to have open-headlamps being referred to retrospectively as Series 1-1/2 E-types being visually seen as an interim change to the Series 1 before the introduction of the Series 2. The term Series 1-1/2 is not, and never has had any factory official recognition, bearing in mind that the open headlamps was a minor modification introduced to satisfy 1967MY USA Safety Regulations, but was standardised across all E-types for all markets for economic/standardization reasons only as there was no legal need outside USA. Open HEadlamps were introduced from January 1967 for E-types sold into the USA market only, legally satisfying 1967 MY safety regulations, but all RHD E-types as well as LHD E-types for European markets (and other non-USA LHD markets) did not receive open headlamps until June/July 1967 - as there was no legal need. So this is why you now get some confusion over LHD E-type bonnets for cars with LHD chassis/car numbers 1E14532 to 1E15889 (LHD OTS) and 1E34113 to 1E34550 (LHD FHC) and 1E77010 to 1E77645 (LHD 2+2) made between January to June/July 1967, as if a particular car was built/sold into the USA market it had an open-headlamp bonnet, but if built/sold into the European market it still had closed headlamps with a glass cover. So anyone with a LHD E-type built between January to July 1967 needs to know where there car was sold new, to establish whether it should have a closed headlamp bonnet, or an open headlamp bonnet now referred to unofficially as a Series 1-1/2.
Things then get more complicated for USA 1968 Model Year Emissions Regulations - so a separate legal framework than the Safety Regulations that introduced ‘open-headlamp’ bonnets (and other safety matters), and again the USA 1968MY Emissions Regulations only applied to E-types built/sold and Certified into the USA market as 1968MY cars - these cars had many engine modifications, of which the fitment of the Twin Stromberg Carburetters was the most visually obvious, but also all certified 1968MY compliant cars have a plaque attached to the car. All RHD E-types and all LHD E-types built/sold into non USA market did not receive any engine modifications, retaining their Triple SU carburetter engines, as they did not need to comply with USA only emissions regulations.
These 1968MY USA market cars were introduced from August/October 1967 from 1E15980 (OTS), 1E34583 (FHC) and 1E77709 (2+2) onwards, but again please note, only for USA market cars, as LHD cars from these Chassis/Car Numbers on built/sold into Europe and other LHD markets other than USA (Including Canada) still had triple-SU non-emissions compliant engines…
Now for reasons that the logic totally escapes me, in certain circles within USA only, someone decided to start ‘unofficially’ referring to these USA market only 1968MY Emissions Compliant E-types as being Series 1-1/2, thus contradicting the unofficial reference to ‘open-headlamp’ cars as being the original use of the term Series 1-1/2 (which of course is still the term used in all other countries). So now these USA market only cars with just open-headlamps as introduced from January 1967 up to the 1968MY emissions compliant cars introduced from August/October 1967 are now unofficially referred to as Series 1-1/4.
So in an international forum such as this JagLovers forum you have total confusion as to what is exactly an ‘unofficial’ Series 1-1/2 E-type. So best to go by the exact Chassis/Car Number, and know whether your car was built/sold new into the USA market, or whether an E-type built/sold into UK or the rest-of-the-world.
But Dan, your 1E14611 is a LHD 4.2 E-type OTS, and if you must a 4.2 Series 1 E-type, but according to its Car No it would have originally had an open-headlamp bonnet, but would still have a triple-SU carburetter (non emissions controlled) engine, so I would unofficially refer to it as a Series 1-1/2 E-type, however am aware that in certain circles within USA some people may refer to it as a Series 1-1/4 E-type 
But totally up to you whether you want to restore it back to factory original condition (only matters to you and if you want to enter a Concours), or whether you want to modify its headlamp arrangement and its bumpers arrangement - both modifications are regularly done…
